机械循环球式转向器分解后应将循环钢球()。
A.清洗后放在一起
B.按轨道清洗后分开放置
C.清洗后按直径大小分轨道放置
D.清洗后按直径大小均分后分别轨道放置
参考答案:B
If there were no automatic washing machines, people would have to wash their clothes ______ hand or ______ hand-operated machines.
A.by; by
B.with; with
C.on; with
D.by; with
哪一种真核生物RNA不需要加工