标识为△/Y,220V/380V的电动机,可以()电路中。
A、△接于220V
B、△接于380V
C、Y接于220V
D、Y接于380V
参考答案:A, D
_______ that he might lose his job, Peter always works extra hours to please his boss.
A.Worrying
B.Having worried
C.Having been worried
D.Worried
在高原、高空环境下,只要吸入气PO2大于60mmHg,Hb氧饱和度仍可达
A.60%~70%B.70%~80%C.80%~90%D.90%以上