氮气置换要间断排放，氮气压力控制在（）MPa以下。
A、0.001
B、0.015
C、0.002
D、0.003
参考答案：D
离心机电机不转时应怎样进行检查？
A pregnant client is taking folic acid. During prenatal teaching, which of the following foods would the nurse recommend as high in folic acid（）
A. Egg yolks.
B. Fruit.
C. Bread.
D. Milk.
