下图中4条曲线分别示意北半球中纬度某湖泊的浮游植物生物量与光照、营养物质含量、气

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问题:

下图中4条曲线分别示意北半球中纬度某湖泊的浮游植物生物量与光照、营养物质含量、气温的年变化。据此完成1—2题。

1、表示光照、营养物质含量、气温年变化的曲线依次是[ ]

A.①②③

B.②①③

C.③②①

D.③①②

2、若营养物质供应充足,则该湖泊浮游植物大量繁殖大约会持续[ ]

A.1个月

B.3个月

C.6个月

D.12个月

考点:主要环境问题的产生和表现
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介绍的通则。

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臭氧在常温下为爆炸性气体,是一种强氧化剂,其密度为1.68(空气为1)。臭氧在水中的溶解度较低(3%)。臭氧稳定性极差,在常温下可自行分解为氧。所以

A.臭氧不能瓶装贮备

B.只能现场生产,立即使用

C.臭氧可作为空气清新剂使用

D.臭氧不可作为空气清新剂使用

E.以上都不对

题型:选择题

短文填词 。

The mobile phone is becoming more and more popular with teenagers.

It shortens the d________ between people. Thanks to the mobile phone,

it is more ________ (方便) for us to contact people. But have you noticed that  

sometimes the mobile phone also b________ embarrassment to us? It's not  

rare to see someone shouting loudly as if there ________ no one else present.

And I'm sure everyone has had some ________ (经历) in which the mobile

phone rings again and again ________ public. People may have various reasons

why they keep the phone w________ all the time, but it interrupts people who

want to concentrate on ________ they're doing. So if you are one of them,

please shut off your mobile phone on formal occasions, e________ when you

are attending class or meetings. It's a respect for both ________ (别人) and  

yourself.

题型:选择题

生物工程所用限制酶功能是()。

A、将核苷酸连接在一起

B、在某一位点切割DNA分子

C、氨基酸结合形成蛋白质

D、限制质粒进入细胞

题型:选择题

向施工封锁区间开行路用列车原则上,每端只准进入一列如超过时其安全措施及运行办法由()规定。

A.铁路局

B.办事处

C.列车调度员

D.车站值班员

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