腹式呼吸训练的要领中错误的是()。
A.吸气时腹部隆起
B.呼气时腹部下陷
C.强调呼气与吸气的时间比例为2:1
D.呼吸深、长、慢
E.全身放松
参考答案:C
If the traffic light is red, you _____ cross the road. It's dangerous. [ ]
A. don't
B. needn't
C. mustn't
D. wouldn't
可行性研究的基本工作程序。