当换热器中两流体均无相变时，尽可能从结构上采用接近逆流的（）的流向以得到较大的传热温差。
A.错流
B.折流
C.层流
D.涡流
参考答案：A
我国社会主义法律体系是以宪法为统帅，以部门法为主体，由下列哪项组成的统一的规范体系（）
A.基本法律和法律
B.法规
C.规章
D.具有法律效力的其他规范性文件
E.以上均是
--What did the teacher say to you just now? ---She asked me ___.
A．if I hace finished my homework
B．if my homework had finished or not
C．whether or not had I finished my homework
D．whether I had finished my homework
