下列关于共同犯罪的说法正确的是（）。
A、是三人以上共同犯罪
B、是二人以上共同故意犯罪
C、可以是过失犯罪
D、按照他们所起的作用分别处罚
参考答案：D
下列化学实验操作中，正确的是（ ）
A．熄灭酒精灯时，用嘴吹灭
B．点燃氢气前，检验氢气纯度
C．稀释浓硫酸时，把水倒入浓硫酸中
D．将实验时多取的药品放回原试剂瓶中
At an outpatient clinic, a client asks the nurse how she can prepare for pregnancy. Which of the following responses by the nurse would be best
A．"Begin an iron supplement of 100 mg daily. "
B．"Supplement your diet with 400 meg of folio acid. "
C．"Avoid raw eggs and cats until conception. "
D．"Receive immunization against toxoplasmosis. "
