F系列可编程序控制器常闭点用()指令。
A、LD
B、LDI
C、OR
D、ORI
参考答案:B
—I believe we've met somewhere before.
—No, _________.
A.it isn't the same
B.it can't be true
C.I don't think so
D.I'd rather not
外关穴位于下列哪条经络上?()
A.手太阳
B.手少阳
C.手阳明
D.足少阳
E.足厥阴