苍蝇的翅第四纵脉直行,触角芒裸,第七纵脉短,第七纵脉不弯曲于第六纵脉前,体有金属光泽为()
A.家蝇
B.厕蝇
C.黑蝇
D.麻蝇
参考答案:C
Shirley ______ a book about Tibet last year, but I don’t know whether she has finished it. [ ]
A. has written
B. wrote
C. had written
D. was writing
项目具有( )特征。
A.一定的约束条件
B.多件性
C.生命周期
D.可重复性
E.一次性