现在完成时专项练习一、单项选择。1、Both his parents look sad . Maybe they _ whats happened to him .(呼和浩特A. knewB. have knownC. must knowD.will know3、Have you met Mr Li _?A. justB. agoC.beforeD. a moment ago4、The famous writer _ one new book in the past two year .A. is writingB.was writingC.wroteD.has written5、Our country _ a lot so far .Yes . I hope it will be even _ .A. has changed ; wellB. changed ; goodC. has changed ; betterD. changed
