腰轮流量计投运时,如前后压差已达()MPa,流量计仍未运转则应停止投运。
A.0.1
B.0.3
C.0.4
D.0.2
参考答案:D
流通过程的商业交易与物流的分离是由于( )造成的。
A.经济复杂
B.商品买卖
C.成本推动
D.效率经济
—What can you see in the picture?
—I can see a farm. And there ______ a lot of animals on it. [ ]
A. is
B. are
C. will be
D. be