A:朝南
B:朝北
C:朝西
D:朝东
The bad weather has been fairly ____ (general).
为每句话选出合适的答语。
A. Ten gifts.
B. Sure. Here you are.
C. Thank you.
D. Great!
E. I'm fine. Thank you.
F. I'm ten.
在NH4NO3、N2、NO2、NO这4种化合物中N元素的化合价有( )