新生儿窒息的复苏措施是（）
A.人工呼吸
B.刺激呼吸
C.维持正常循环
D.复苏器加压给氧
E.清除呼吸道分泌物
参考答案：A, B, C, D, E
离心泵的叶轮直径发生变化则（）也随之变化。
A.扬程、流量、效率
B.扬程、流量、轴功率
C.流量、轴功率、效率
D.扬程、轴功率、效率
Evidence has been found through years of study______ children’s early sleeping problem likely to continue when they grow up.
A．why
B．how
C．whether
D．that
