一批零部件具有互相替换使用的特性为互换性。（）
参考答案：错
判定支气管哮喘最有意义的指标是（）
A.肺活量
B.嗜酸性粒细胞数
C.症状和体征
D.血气分析
E.X线肺野透亮度的变化
He said he would prefer ______ others rather than ______ by others.
A． to help; to help
B． to help; be helped
C． helping; helped
D． helping; to be helped
