It will______us several years to learn a foreign language well.
---What’s wrong with you, Dave?---My homework can’t be __________ on time because I’ve left it at home.
---________ fine day! Let’s go hiking together. ---Good idea!
---What do you think of the twin sisters?---They are quite different. One is outgoing, __________ is very serious.
The old man __________ eats junk food, does he?
-- Mom, when shall we go to Weifang Museum this weekend?-- Oh, sorry. I'm going to Beijing for a meeting. ___Saturday __ Sunday is OK.