Is the following sentence correct?     A number of researchers are expected to attend the conference   Notice that the sentence is using the plural verb "are" after "researchers" but I don't know if it needs the singular verb "is" instead, since it says "A number" before "researchers".
I looked up a few grammar-teaching websites (in Chinese language). The website says many people do not use the phrase "A xxx of" correctly because they do not identify the subject of the phrase correctly.   The website says phrases like "A range of; A high percentage of" is singular, while "a number of; a group of; a couple of; a total of" is plural.  Therefore according to the website, the correct sentences should be as follows.     A wide range of courses is available. ("A wide range" is the subject)      A high percentage of peptides that are made of amino acids is present   in the sample. ("A high percentage" is the subject)      A number/ group/ couple of people were killed in the earthquake.("people" is the subject )       A total of 230 employees were laid off. ("employees" is the subject)   I don't get the pattern here. All of this looks (or should I use "look"?) arbitrary to me. In fact I thought this phrase is supposed to be arbitrary and whether the phrase is plural or singular should depend on the the person's own judgment.   How do I identify the correct subject in the "A xxx of" phrase?
Do Inverters change the lithium-ion batterie's mA capacity and wattage? let me say if I have a pack of lithium batteries connected in series and parallels, and i want to connect it to an Inverter, BUT...BEFORE I connect it to inverter, lets say it gives out 12 volts "hypothetically" some informations like 3.7 volt batteries, and 2500 mAh,  lets say then the pack gives 12 volts in DC and hypothetically again I calculate it ((still in DC)) is .....  W = V* Amp ... then it means wattage = 11.1 V * 5 Ah which is 55.5 W. then we got 55.5 watts, THEN....after we want to change the dc into ac it gives you 120 volts "please hypothetically" just answer me this, ARE the Wattage And Ampere are remains the same as DC? what would it be the result after AC? According to ,  The collection of all algebraic objects of a given type will usually be a proper class. Examples include the class of all groups, the class of all vector spaces, and many others. In category theory, a category whose collection of objects forms a proper class (or whose collection of morphisms forms a proper class) is called a large category.  I am aware of Russell's Paradox, which explains why not everything is a set, but how can we show the collection of all groups is a proper class? $\displaystyle\int_{0}^{2\pi}\frac{1}{a+ \cos\theta}\,d\theta$ Entire function bounded by a polynomial is a polynomial Suppose that an entire function $f(z)$ satisfies $\left|f(z)\right|\leq k\left|z\right|^n$ for sufficiently large $\left|z\right|$, where $n\in\mathbb{Z^+}$ and $k&gt;0$ is constant. Show that $f$ is a polynomial of degree at most $n$. How can I use the `--multi-dex` option? Start a longtable in Latex at top of next page I want to use the longtable environment for a table. However, I do not know how to place it at the top of the next page, as I can do with the table environment. Do you know how to do it? Exporting Data From Salesforce - REST or SOAP? We have a requirement where we need to export records from salesforce tables into our application programmatically. I am reading on the various API's for data integration from salesforce mainly SOAP vs REST API's.  From what I understand, REST should be used when the web service requests are from mobile devices or browser based clients (since they understand JSON). Is that true? If that's the case how do Bulk REST API's fit the bill (since they are meant for bulk data transfers)?  I would like to get your thoughts on what are pros and cons in using SOAP or REST API's to export data records. Note that the requests are being made a java ee server application programmatically. After retrieving the records (probably in batches) from salesforce records we process (validate, filter etc) them and load them in our internal tables.  Thanks. Recently I ran across the sentence:     "Just why the law prescribed thirty-nine lashes instead of forty or forty-one and so on, must needs remain unanswered."   How did a plural verb like "needs" wind up as an adverb?  Is it alone in this phenomenon, or are there other examples that appear to be an odd misplacement of a second verb, but are actually adverbs as well? Why is it necessary to sample from the posterior distribution if we already KNOW the posterior distribution? My understanding is that when using a Bayesian approach to estimate parameter values:   The posterior distribution is the combination of the prior distribution and the likelihood distribution. We simulate this by generating a sample from the posterior distribution (e.g., using a Metropolis-Hasting algorithm to generate values, and accept them if they are above a certain threshold of probability to belong to the posterior distribution). Once we have generated this sample, we use it to approximate the posterior distribution, and things like its mean.   But, I feel like I must be misunderstanding something. It sounds like we have a posterior distribution and then sample from it, and then use that sample as an approximation of the posterior distribution. But if we have the posterior distribution to begin with why do we need to sample from it to approximate it? Find the last $2$ digits of $$\large7^{7^{7^{10217}}}$$   So far I have: $17\cdot 601=10217$ and $7=7 \pmod{10}$. Any help greatly appreciated. What is the domain of $x^x$ as a real valued function? Consider the function $f(x) = x^x$.  Wolfram alpha tells me that this function's domain is $x : x&gt;0$, $x \in \mathbb{R}$. I can't see why it cannot be defined for a number like $(-2)$. I mean $(-2)^{-2}=0.25$, the same Wolfram Alpha told me. I realize that fractional powers for negative numbers may cause problems, but it could be defined for integers. Thanks for any help. Reading the Result of Traceroute When you use tracert www.example.com in the command prompt, what exactly does the returned information tell you, and how does it go about getting that information. Up until now I have only used traceroute to get the I.P. address of a website without really thinking about the bigger purpose of traceroute. Is there any way to have BibTeX or biblatex insert a bibliography without having citations in the body of the document itself? Maybe a way to hide the in-text citations, so that BibTeX still sees them and includes them in the bibliography, but does not print them in the body? Is there a max array length limit in C++? Is there a max length for an array in C++?  Is it a C++ limit or does it depend on my machine? Is it tweakable? Does it depend on the type the array is made of?  Can I break that limit somehow or do I have to search for a better way of storing information? And what should be the simplest way?  What I have to do is storing long long int on an array, I'm working in a Linux environment. My question is: what do I have to do if I need to store an array of N long long integers with N > 10 digits?  I need this because I'm writing some cryptographic algorithm (as for example the p-Pollard) for school, and hit this wall of integers and length of arrays representation. Why does Hermione say she hadn't used a memory charm before? After the wedding, Hermione has to use a memory charm on two Death Eaters, where she states that she has never done it before, but she knows the theory. However, she states that before she left on her adventure, she made her parents forget her, and move to Australia. Is this a contradiction, or is there an explanation? In ubuntu 11.04 there was a workaround using gconf-editor and setting key /apps/gnome_settings_daemon/plugins/xrandr/active to false.  However there is no such key in gconf-manager using ubuntu 11.10 (gnome 3). SSL password on apache2 restart I setup wildcard SSL certificate from Godaddy on Apache2. Whenever the server restarts it asks for the passphrase for the SSL certificate's private key.    What's the best way to remove this obstacle to restarts, because when logfile rotation restart occurs in the middle of the night, the server doesn't come back up, and I get an unhappy client call in the morning, as it is a shared server. 'AND' vs '&&' as operator Prove that the equation $x^2-y^2 = 2002$ has no integer solution How can I tell whether a circle and a rectangle intersect in 2D Euclidean space? (i.e. classic 2D geometry)