配电变压器如一直在正常负荷下运行，可考虑每（）年大修一次。
A.9
B.10
C.11
D.12
参考答案：C
新生儿机械通气的指征有哪些？
I saw my sister help _____ food to the kids just now.[ ]
A. give out
B. gave out
C. give up
D. gave up
