舰艇不得悬挂（）的国旗。
A、破损
B、污损
C、褪色
D、不合规格
E、以上都不对
参考答案：A, B, C, D
Much of this success is the work of students, and the support from teachers.[ ]
A. because, of
B. because of, with
C. because of, within
润滑油为何上油管细，回油管粗？
