大环内酯类的抗菌机制是()
A.影响叶酸代谢
B.影响胞浆膜的通透性
C.抑制DNA的合成
D.抑制蛋由质合成的全过程
E.抑制核酸合成
参考答案:D
It took him ____ to find the key to the drawer.
A.one and half hours
B.one and a half hours
C.one and a half hour
D.one and half hour
FIR滤波器必是稳定的。()