A:充分不必要条件
B:必要不充分条件
C:充要条件;
D:既不充分也不必要条件
先化简: (x−xx+1)÷(1+1x2−1) ,然后在-1,0,1,2四个数中选一个你认为合适的数代入求值.
May I take your ____ (点菜)?
When will Sally probably go to Shanghai?