转子流量计中流体流动方向是()。
A、自上而下
B、自下而上
C、都可以
参考答案:B
_____ you'll have a great chance of finding a suitable job if you have done some part-time jobs.[ ]
A. Generally
B. Especially
C. Mainly
D. Surprisingly
国标规定的聚乙烯命名方法,其中特征()是聚乙烯的缩写代号。
A.单元1
B.单元2
C.单元3
D.单元4