支配二腹肌前腹的神经是( )
A.面神经
B.上颌神经
C.下牙槽神经
D.三叉神经
E.迷走神经
参考答案:D
Grover Cleveland was the first president () in the White House.
A. got married
B. to get married
C. has got married
D. was married
设有区域D:x2+y2≤y,x≥0,f(x,y)在D上连续,且
求f(x,y).