缓和段有()、()和()三种。
参考答案:双扭线、回旋线、抛物线
-I'm going to a party this evening.
!
A.I'd love to
B.Here you are
C.Not at all
D.Have a good time
口对口人工呼吸时,救护人向触电者口内吹气时,应使触电者鼻紧闭,而让触电者自行呼气时,应使其鼻张开。