1.New things always have to face difficulties_they grow.A.when B.as C.since D.during 2.When the teacher came in,the students_.A.are talking happily B.were talking happily C.talked happily D.has been talking happily 3.I was about to go out for a walk_he came.A.when B.while C.as D.since 4.His German isn't very good even_he's lived in Germany for over two years.A.how B.though C.whether D.what 有急用,