1．Why don't you put the apples in the fridge？They will
________ fresh for several days.
A．be stayed B．stay
C．be staying D．have stayed
答案与解析：B stay是不及物动词，意为“保持”，无被动语态和进行时。
2．He wouldn't help us even if we were good friends；________ we treated him badly before.
A．let alone B．leave alone
C．leave out D．leave off
答案：A
