疾病的时间分布中，不包括（） A.短期波动 B.长期趋势 C.季节性 D.局限性 E

征税对象的全部数额都按照相应等级的税率征税的税率形式是（）。

A.金额累进税率

B.超额累进税率

C.超率累进税率

D.超倍累进税率

通读下面的对话，然后根据上下文补全对话内容。

A: Have you (1) r_________ today's newspaper?

B: No, I haven't. (2) W_________ there any important news?

A: There's a (3) r_________ about the population of our country. It says we have got another 16,000,000

    people this year.

B: Oh, the population is growing faster and (4) f______.

A: If the population goes on (5) g________, it will be the (6) b________ problem in our country.

B: Of course. The population of the babies born in one year in China is (7) a________ as large as the population

    of Australia.

A: I'm afraid there will be only (8) s________ room for us some day.

B: But if every family has only (9) o________ baby, things will turn (10) b________.

关于DNA双螺旋结构的叙述，哪一项是错误的

A．磷酸戊糖位于螺旋外侧，碱基位于内侧
B．两条链通过碱基之间的氢键维系
C．为右手螺旋，每个螺旋为10个碱基对
D．碱基配对有摆动现象
E．螺旋的直径为2nm

史集

矿井充水的主要因素有：大气降水、地表水、含水层水老窑采空区水、断层水、封闭不良的钻孔水、采矿活动造成的（）水等。

A.三带水

B.老塘水

C.小窑水

D.岩溶水