婴幼儿哮喘与喘息性肺炎的根本区别为（）
A.反复喘息发作
B.血细胞及分类正常
C.可应用β受体激动剂
D.年龄小于3岁
E.气道高反应
参考答案：E
— _____________?
—I’m sorry, I’m busy cooking. Do it yourself.
A．Dad, could I use your CD player
B．Mom, could you please clean my bedroom
C．Tom, could you please make your bed
D．Jack , could I borrow your bike
盈亏平衡分析的假设条件之一是，产量（）销售量。
A.大于
B.小于
C.等于
D.不等于
