单项选择题
Don't disturb me. I（）letters all morning and have written ten so far.
A.write B.have written C.was writing D.have been writing
单项选择题 Mr. Smith（）a most important part in the development of our city.
单项选择题 Could you tell me where Mr. Lake is? ---（）
单项选择题 What a lovely day! Why not go swimming this afternoon? —（）
