PLC的L+及M端口间电压一般是()伏。
A.DC24V
B.DC36V
C.AC110V
D.AC220V
参考答案:A
His grandparents live ____ in a small house, but they don’t feel _______.
A.lonely; alone
B.alone; lonely
C.lonely; lonely
D.alone; alone
These teenagers don’t know much of the world yet; that’s why they are so easily _____ .
A.taken in
B.taken up
C.taken on
D.taken off