Let x be the sum of a and b.

设x为a加b之和。

《牛津词典》

According to the X-ray, your disease may be diagnosed as T. B.

根据 X 光检查，你的病可能是肺结核。

youdao

X It's a matrix times some unknown vector, x, B equals some known vector, B How do we solve that?

是一个矩阵乘以一些未知的向量，等于一些已知的向量，怎么解？

youdao

When he is clear of the B-52, he starts the X-15's rocket engine.

VOA: special.2010.07.07

So they're the same shape, this is the shape of the orbital or the shape of the wave function, and we can call this either 2 p x a being combined with 2 p x b, or we could say since it's the same shape, it's 2 p y a being combined with 2 p y b.

它们形状是一样的，这是轨道的形状或者波函数的形状，我们叫它2pxa和2pxb结合，或者我们说因为它们的形状是一样的，它是2pya和2pyb结合。

麻省理工公开课 - 化学原理课程节选

pxa So what happens when we add a 2 p a and we subtract from it a 2 p x b, or the same with a 2 p y a subtracting a 2 p y b, is that we're actually going to cancel out the wave function in the center, so we now have 2 nodal planes.

当我们用,减去2pxb时，或者是2pya减去2pyb时，我们会消去,中间的波函数，所以现在我们有两个节面。

麻省理工公开课 - 化学原理课程节选

Former X Factor star Misha B has scored her first top 10 hit with Do You Think Of Me.

BBC: Robbie Williams

Oh, we almost forgot -- they've boosted out the keyboard in favor of a more useful D-pad and A, B, X, Y button formation -- which is, needless to say, awesome for playing awesome games.

ENGADGET: Seabright PC430 "micro PC" spurns keyboard, not coolness

You'll need to have a skin test for tuberculosis, a chest X-ray and a test for hepatitis B before taking infliximab.

CNN: Ulcerative colitis