— Do we have to finish our homework this afternoon?
— Yes, you ________.
A:must
B:can
C:may
D:need
(Ⅰ)恰好有两家造纸厂必须整改的概率;
(Ⅱ)至少要关闭一家造纸厂的概率;
(Ⅲ)平均多少家造纸厂需要整改?(其中( 910 )5≈ 59100 )
描一描,写一写。
绿色植物在夜晚一般不能进行光合作用,原因是缺少外界条件( )
— Does he like singing?
— No,he doesn't. He likes ____.