支气管哮喘最确定的发病危险因素是（）
A.内分泌因素
B.遗传因素
C.神经精神因素
D.非特异性刺激物
E.特应质
参考答案：E
看图补全句子。
1. They are pretty________. I like them.
2. It's ________ in Moscow.
3. The______ is heavy. I can't carry it.
4.I like _________. What about you?
5. I have a cool_________. It's my birthday gift.
高技术企业与工业整体水平的比较及内部构成
规模以上工业企业的R&D经费支出与科技活动经费支出的比例（）。
A．5：9
B．10：17
C．15：20
D．20：25
They are pretty________. I like them.
It's ________ in Moscow.
The______ is heavy. I can't carry it.
I like _________. What about you?
I have a cool_________. It's my birthday gift.