48. _______ you begin the work , you must carry it out through to the end.
A. When B. Though C. Sometimes D. Once
49. I’ll start early , _______ it is dark or light .
A. however C. whether C. if D. though
50. He is so strongly built that he looks _______ he could lift an elephant.
A. if B. as if C. like D> that
答案：
名词性从句
1-5.CDCDB
6-10.BABCD
11-15.ADCCA
16-20.DABCA
21-25.BBDDA
26-30.BCDCC
31-35.ABCDC
36-40.DABBC
状语从句
状语从句Key:
1.CCCDB
6.BBBBD
11.DCBBD
16.BCAAB
21.ABACA
26.CCBAC
31.BDDAC
36.CADAD
41.CDAAC
46.AADBB