It takes time to build ______ when you are learning a difficult skill.
No one ________be more generous; he has a heart of gold.
—You needn’ t take an umbrella.It isn’t going to rain. —Well,I don’t know.It________do.
Since nobody gave him any help,he________have done the research on his own.
-I'm afraid that I couldn't pass the examination. -As a student,you need to believe in yourself________you have the ability to achieve any________goal.
-Sir,may I borrow some new books? -Sorry,you can't________you haven't turn back those you borrowed one month ago.