一侧上尿路完全梗阻一定时间可使肾功能会完全丧失，梗阻时限是（）.
A.1周
B.2周
C.4周
D.6周
E.3个月
参考答案：D
All of the boys_____ supper when I got there. [ ]
A. is having
B. was having
C. are having
D. were having
直分销业务按照销售业务类型一般分为以下哪几种（）。
A、定量销售
B、非定量销售
C、实收量交接销售
D、油品直销
