—I'll go to Beijing.
A:Where
B:What
C:When
先化简,再求值:( x2+xx2−1−11−x ) ÷(x2+3xx−1−1) ,其中x=2.
设集合A=x,y|x24+y216=1,B=x,y|y=3x,则A∩B的子集的个数是( )
Each of the boys ____ (carry) a bag of books at the moment.
关于x的方程(a-5)x2-4x-1=0有实数根,则a满足( )