The promotion is valid by December 5th 1) I need to say the promotion will be invalid on December 6th and while we have not reached that date, the promotion will be valid. What should I say:     A) The promotion is valid up to December 5th.    B) The promotion is valid until December 5th.    C) The promotion is valid by December 5th.    I think only 'C' is correct here.   2) I need to say the promotion is valid from date ‘X’ to date ‘Y’. After the date ‘Y’ the promotion will be invalid. How shall I say it:     A) They have great promotion from January fifth, until January 8th up to 50% off.    B) They have great promotion from January fifth, up to January 8th up to 50% off.    For me both work here and have exactly identical meanings. Am I right?
(Up to / until / by) 50% off I wonder if someone could tell me which choice works in the following sentence and why the others do not work: (From my point of view, all of these choices work in this context.)  They have great promotion till January 5th......50% off. a) up to; b) until; c) by
Can EU citizens travel to UK after Brexit with just an identity card? How do you change age settings on ROBLOX? How do you set your age settings on ROBLOX if you accidentally set to under 13? I accidentally put 2008 instead of 1998 in the sign up section. Is there any way to change this, as in settings, age settings are greyed out. Product of manifolds & orientability I'm studying orientability of manifolds currently and I'm having trouble to prove the following: $M\times N$ is orientable iff $M$ and $N$ are orientable.   I am able to prove that the product is orientable if components are orientable (chart is $\{(U_\alpha\times V_{\beta},\phi_\alpha\times \psi_\beta):(\alpha,\beta)\in A\times B \}$, and $\det J=\det J_1 \det J_2&gt;0$ by Cauchy-Binet's theorem), but I don't know how to prove the other direction.   So why this holds: if $M\times N$ is orientable, then $M$ and $N$ are orientable?  Thanks in advance. My question is whether $x/x$ is always equal to $1$. I am mostly intersted in real numbers and particularly wonder whether $x/x$ is defined at $x=0$.  On one hand the division should simplify to $1$, on the other hand you should not be allowed to divide by zero.   I have been trying to find whether the simplification 'goes first' or whether the division causes trouble first, but it has proven impossible for me to find usefull search terms.     Note that this question arose after reading  and its first comment. "Specially" vs "especially" When should I use specially and when especially? How to use inotifywait to watch a directory for creation of files of a specific extension I have seen .      You should consider using inotifywait, as an example:  inotifywait -m /path -e create -e moved_to |     while read path action file; do         echo "The file '$file' appeared in directory '$path' via '$action'"         # do something with the file     done    My question is that, the above script watches a directory for creation of files of any type, but how do I modify the inotifywait command to report only when a file of certain type/extension is created (or moved into the directory) - e.g. it should report when any .xml file is created.  WHAT I TRIED:  I have run the inotifywait --help command, and have read the command line options. It has --exclude &lt;pattern&gt; and --excludei &lt;pattern&gt; commands to EXCLUDE files of certain types (by using regEx), but I need a way to INCLUDE just the files of a certain type/extension. "physical block size is 2048 bytes, but Linux says it is 512" when formatting USB - How to create a bootable USB without this error How do I use method overriding in this case? Is there a way to recover files from a storage device partially overwritten with dd? I'm an idiot, I was writing an image to a USB drive using dd when instead of typing /dev/sdb I typed /dev/sdd and wrote the 135mb image to my 750gb External Hardrive full of files. Is there ANY possibility of recovering the files or did dd completely zero out the drive? Please help, as this is one of the lowest points of my life EVER.  dd finished writing the 135mb image in 5 seconds, so I didn't have a chance to stop it. By the time I knew what happened to was too late. The command was as follows:   sudo dd if=generic.img of=/dev/sdd bs=1M   EDIT2: The External Harddrive's filesystem was FAT32(I've had the drive for awhile and FAT32 was the most Universal FS at the time). I also have a 2TB drive I just got which I was planning on moving most of the files to from the 750gb, If needed I can use it to transfer the Recovered files to. Meaning of probability notations $P(z;d,w)$ and $P(z|d,w)$ What is the difference in meaning between the notation $P(z;d,w)$ and $P(z|d,w)$ which are commonly used in many books and papers? I would like to remove page numbering on a specific page. However, the header and footer should remain intact. If I try:  \thispagestyle{empty}   The header and footer disappear. What is the recommended way of removing just the page number? House address is not listed on Google Maps When I search for my address on Google Maps it cannot be found which means I can't order takeaway etc.  Is there a way of adding my address to Google Maps or even add a street address?  I want the address to be publicly available so others can search it. When a 0-1-matrix with exactly two 1’s on each column and on each row is non-degenerated? [1] Display current layout (language code/country flag) in keyboard indicator Just upgraded from 10.04 to 10.10, and the keyboard indicator applet no longer displays the two-letter country code for the active layout.  This is terrible. Is this the default behaviour? Anyone using two layouts can't tell which language they're in.  I can't seem to find the setting for this, it used to be in the preferences for keyboard layout.  Update 1: In case this wasn't obvious - I have two keyboard layouts - English and Hebrew. I just upgraded form 10.04, where the country code (USA/IL) was displayed, overlaid on the flag.  Now all I get is a vague keyboard icon, and can't find the settings for this.  Update 2: this seems to be a , and is now back in Maverick Problem Currently, I am playing on a server where hoppers transport items at the rate of 64 items a second, and this has proved very difficult to build a sorter for. I'm not at all proficient in Redstone building but have tried building basic sorters and ones that I have found on YouTube and I haven't gotten anything to work. Solution Hopefully one of you is really good at Redstone and can help me design a sorter that can work under these conditions. (I need the sorter that can sort items while I AFK kill witches with a looting 47 sword P.S. most of the problem is with the sorter itself because no items will stay in the sorter hopper (bc the whole stack goes into the chest so the hopper doesn't have anything to go off of to sort) so any solution to that would be helpful as well. "The train will leave" vs. "is going to leave" vs. "leaves" vs. "is leaving" I came across this formula in a list:  The number of ways of distributing $n$ identical objects among $r$ groups such that each group can have $0$ or more $(\le n)$ objects  I know that standard way of doing this is to solve the problem of distributing n identical objects and $(r-1)$ partitions among themselves which can be done in $C(n+r-1,r-1)$ ways.   But I am unable to prove to myself why it is not $(r+1)^n$.  Because each of the n objects has r+1 choices, either group1, group2,... group r or none at all. What is a good book to study linear algebra? I'm looking for a book to learn Algebra. The programme is the following. The units marked with a $\star$ are the ones I'm most interested in (in the sense I know nothing about) and those with a $\circ$ are those which I'm mildly comfortable with. The ones that aren't marked shouldn't be of importance. Any important topic inside a unite will be boldfaced.  U1: Vector Algebra. Points in the $n$-dimensional space. Vectors. Scalar product. Norm. Lines and planes. Vectorial product.  $\circ$ U2: Vector Spaces. Definition. Subspaces. Linear independence. Linear combination. Generating systems. Basis. Dimesion. Sum and intersection of subspaces. Direct sum. Spaces with inner products.  $\circ$  U3: Matrices and determinants. Matrix Spaces. Sum and product of matrices. Linear ecuations. Gauss-Jordan elimination. Range. Roché Frobenius Theorem. Determinants. Properties. Determinant of a product. Determinants and inverses.  $\star$ U4: Linear transformations. Definition. Nucleus and image. Monomorphisms, epimorphisms and isomorphisms. Composition of linear transformations. Inverse linear tranforms.  U5: Complex numbers and polynomials. Complex numbers. Operations. Binomial and trigonometric form. De Möivre's Theorem.  Solving equations. Polynomials. Degree. Operations. Roots. Remainder theorem. Factorial decomposition. FTA. Lagrange interpolation.  $\star$ U6: Linear transformations and matrices. Matrix of a linear transformation. Matrix of the composition. Matrix of the inverse. Base changes.   $\star$ U7: Eigen values and eigen vectors Eigen values and eigen vectors. Characteristc polynomial. Aplications. Invariant subspaces. Diagonalization.   To let you know, I own a copy of Apostol's Calculus $\mathrm I $ which has some of those topics, precisely:   Linear Spaces Linear Transformations and Matrices.   I also have a copy of Apostol's second book of Calc $\mathrm II$which continues with   Determinants Eigenvalues and eigenvectors Eigenvalues of operators in Euclidean spaces.   I was reccommended Linear Algebra by Armando Rojo and have Linear Algebra by , which seems quite a good text.   What do you reccomend? Random plot based on a specific random seed Is colour, as represented using primary colours, accurate only to humans? Slightly biological, hopefully physical enough to be answered.  Suppose a magenta hue is represented by a mix of red and blue pigment. This is all very well for a creature with red and blue photoreceptors, but suppose it was seen by a creature which had a magenta-sensitive receptor, but no red or blue. Would the colour appear the same (insomuch as a qualititave concept can appear the same, I suppose I mean 'Would they interpret it as colour of the same wavelength?')?  The crux of my question is, do the particular bands in which photoreceptors are activated affect vision of additive, as opposed to pure, hues?  Finally, completely off-topic, but if there happens to be a biologist around, do animals on the whole have similar photoreceptors, or are they placed largely randomly?  Thanks, Wyatt