Are there one or more words that take only a singular form?
Does English have any singularia tantum besides mass nouns?
How to write a Hello World application in Java? Prove p-adic valuation is completely additive for prime p Delayed eraser experiment (Kim experiment) Will I receive an interference pattern on D0 detector   if D1, D2, D3, D4 exist in the set up of the experiment, but they are thousands of light years far? Simply, to set up the experiment so that I detect all of the signal photons on D0 before I detect any of idler photons! I'm using uninstall.php for my plugin to delete all the traces my plugin did to a site on uninstall (delete). I did it in a good way, but even after the deletion there are some fields in the options table:   uninstall_plugins recently_activated _site_transient_update_plugins   in these options there are multiple values from other plugins too.  How can I take care of such traces, how can I remove all those traces too?  I checked WooCommerce and found they leave no traces after there deletion, if the "delete data" checkbox is checked.  How can I do so? When I ping I have this display:  &gt; ping -i 4 www.google.fr  64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=503 ttl=46 time=45.5 ms ....... ....... 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=508 ttl=46 time=44.9 ms 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=509 ttl=46 time=45.1 ms   I'd like to have the time of the ping before.   Something like:  &gt; (right functions) + ping -i 7 www.google.fr  mardi 15 mai 2012, 10:29:06 (UTC+0200) - 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=503 ttl=46 time=45.5 ms ....... ....... mardi 15 mai 2012, 10:29:13 (UTC+0200) - 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=508 ttl=46 time=44.9 ms mardi 15 mai 2012, 10:29:20 (UTC+0200) - 64 bytes from wi-in-f94.1e100.net (173.194.67.94): icmp_seq=509 ttl=46 time=45.1 ms   How would you do this in a command line (if it's possible)? Why does a window become a mirror at night? In day, when you look in the room through the window out, you can clearly see what happens outside. At night when it's dark outside but there's light inside you can look in the window but it becomes a mirror.  Why? If $a^3 =a$ for all $a$ in a ring $R$, then $R$ is commutative. Let $R$ be a ring, where $a^{3} = a$ for all $a\in R$. Prove that $R$ must be a commutative ring. Does Earth really have two high-tide bulges on opposite sides? The bit that makes sense – tidal forces My physics teacher explained that most tidal effect is caused by the Moon rotating around the Earth, and some also by the Sun. They said that in the Earth and Moon system, the bodies are in freefall about each other. But that points on the surface of Earth, not being at Earth's centre of gravity, experience a slightly different pulls towards the Moon. The pull is a little greater if they are on the Moon's side, and slightly lesser if they are on the side away from the Moon. Once freefall is removed, on the Moon side this feels like a pull towards the Moon and on the the opposite side it feels like a repulsion from the Moon. This makes sense to me, and is backed up by other questions and answers here, like  and also  Phys.SE question. The bit that doesn't make sense – tidal bulges They also said that there are &quot;tidal bulges&quot; on opposite sides of the Earth caused by these forces. The bulges stay still relative to the Moon and Earth rotating through the bulges explains why we get two tides a day. They drew a picture like this one…  An image search for  finds hundreds of similar examples, and  from a scientist on Twitter. …But, if there is a tidal bulge on both sides of Earth, like a big wave with two peaks going round and around, how can an island, like Great Britain where I live, simultaneously have a high tide on one side and a low tide on the other? For example:   on the West coast  on the East  Two ports with tides 6 hours, or 180º apart. It's high tide at one while low tide at the other. But they are only  by road. Great Britain is much smaller than Earth. It's probably not even as big as the letter &quot;A&quot; in the word &quot;TIDAL&quot; in that picture.  To prove this isn't just Britain being a crazy anomaly, here is another example from New Zealand:     Two ports that are 180º (6 hours) apart, but separated by  through a national park. New Zealand, unlike the UK, is in fairly open ocean. To prove that $f_n(x) = \frac{nx}{1+n^2x^2}$ does not uniformly converge to $f(x) = 0$ on $[0,1]$ Convert from a specifc range to another one Don't count non-printing characters, HTML comments or other content not displayed toward minimum character requirements Applying an ellipsis to multiline text Naming threads and thread-pools of ExecutorService If n is an odd integer, show there exists a positive integer k such that 2^k mod n = 1. Just for curiosity, sometimes while installing software throught apt-get install software_name the terminal prompt me for a confirmation "type Yes or No", but not allways.  I dont mean the sudo password prompt, but the message "Will be downloaded and configrated XXX Kb, continue?" (or something similar)  Why? find spectrum matrix A Let $A = \left[ \begin{array}{*{20}{c}} 0&amp;b&amp;0&amp;0&amp;0&amp;0\\ c&amp;0&amp;b&amp;0&amp;0&amp;0\\ 0&amp;c&amp;0&amp;b&amp;0&amp;0\\ 0&amp;0&amp;c&amp;0&amp;b&amp;0\\ 0&amp;0&amp;0&amp;c&amp;0&amp;b\\ 0&amp;0&amp;0&amp;0&amp;c&amp;0 \end{array} \right]_{n \times n}$.  Why does matrix $A$ have spectrum $\sigma (A) = \left\{ 2\sqrt {bc} \cos \left(\frac{\pi k}{n + 1}\right):k = 1,2,\ldots,n \right\}$? it has the guide for 12.10 but not newer ones plz someone help How do I create a vertical version of \not? In this case what is correct?        Keep Tom and I updated.      or         Keep Tom and me updated.      I understand that me is an object pronoun. And therefore I feel the second option is correct.  Especially, because I would say "Keep him updated" and also "Keep me updated". Instead of "Keep he updated" or "Keep I updated". But something about saying "Keep him and me updated" feels wrong.  However I am not sure, because several people have told me that in this case I is the correct option because it is being used in conjunction with a name (Tom) and not a pronoun. Is that correct? How to compile bibtex with TeXstudio? I am trying to use bibtex for the first time. I am on windows 7, using TeXstudio. I am trying to follow the steps of .  I have created a .bib file, put it in the right directory and written the code in my .tex file. However, I do not know how to compile bibtex with TeXstudio (I looked around in the menus but didn't find it).   Most tutorials I found don't explain how to do it, or say to run a command, which I'm not sure how to do.  Any help much appreciated!