After retirement, learning a musical instrument may be harder than ______ when you were a kid.

Tom is as _____ as Mary.

72. You can’ t throw the waste everywhere. You should keep the classroom _________.

－I’m thinkingof the test tomorrow. I’m afraid I can’t pass this time. －! I’m sure you’ll make it.

Why didn’t you follow us to get on the underground— I tried to, but it started moving _________ I could get on it.