1.You can go and take a rest.I'll see to it that the job -----finished in time.为什么选择B不选择A呢?A.must be B.is C.be D.has2.She ----- her hairstyle in her hometown before she came to London for a better job.为什么不选择B呢?A.changed B.has changed3.Roman Empire ------for centuries.为什么选择B不选择C呢?A.has existed B.exsisted C.was exsisting4.She ------law the moment she has finished middle school.为什么不选A呢?A.is going to study B.is to study5.Great efforts to increase wheat production must be made if bread shortage -----avoided.为什么选择A呢?这句话的意思是什么?A.was about to B.was to谢谢啦。