第一次工业革命中最有影响力的技术发明是 [ ]
A.珍妮纺纱机
B.联动式蒸汽机
C.蒸汽机车
D.“搅炼和碾压法”
答案:B
Liu Yuping is from a beautiful country.
A.lives in
B.was born in
C.comes from
D.likes going to
LOR选择开关的定义?