单项选择题
Tom（）since he lost his job three weeks ago.
A.has employed B.was unemployed C.had been unemployed D.has been unemployed
单项选择题 — What a lovely day! Why not go swimming this afternoon? —（）
单项选择题 -- Do you mind if I smoke here? ----（）
单项选择题 — Has Mr. Smith had an accident? —（）
