测量聚合物固含量所用的称量瓶规格是()。
A.内径30mm,高40mm
B.内径40mm,高30mm
C.内径50mm,高20mm
D.内径60mm,高20mm
参考答案:B
In order to get ________ enough travel experience, they have planned _________ bicycle journey along the longest river of the country.
A.an; /
B.an; a
C./; /
D./; a
分配阀在“初制动”位时,主阀开通制动管到()的通路。
A、局减室
B、初制风缸
C、工作风缸
D、均衡风缸