在控制性详细规划阶段，用地分类应达到()。A.大类为主，中类为辅 B.中类为主 C.

It snowed _____ this February. Many people had to stay at home instead of going travelling. [ ]

A. heavily

B. quickly

C. slowly

D. weakly

____ English for more than six years, he can speak and work very well with that businessman from England. [ ]

A. To have learned

B. To learn

C. Learning

D. Having learned

画线段AB=1cm，延长线段AB到C，使BC=2cm，已知D是BC的中点，则线段AD= _________ cm．

空压站操作间的噪声应低于()dB。

A．65

B．75

C．85

D．90

急性肺淤血时最典型的症状是()

A．心悸

B．胸闷

C．呼吸困难

D．粉红色泡沫痰

E．铁锈色痰