马克思主义唯物史观认为，（）决定上层建筑。
A.经济基础
B.社会存在
C.社会意识
参考答案：A
已知集合A={a|a＜x＜5}，B={x|x≥2}，且满足A⊆B，求实数a的取值范围．
Don't talk loudly at the meeting. If you ________, you will have to leave. [ ]
A. do
B. are
C. did
