化简求值：（1）1-2sinαcosαcos2α-sin2α•1+2sinαco

任务型阅读。

     Most children like watching TV. It's very interesting. By watching TV they can see and learn a lot and

know many things about their  country  and  the  world. Of  course,  they can also learn on the radio. But

they can learn better and more  easily on TV. Why? Because  they  can hear and watch at the same time.

But they can't see anything over  the  radio, TV  helps  to  open  children's  eyes. TV helps  to open their

brains (大脑),too. They can learn newer and better ways of doing things. They may find the world is now

smaller than before.Many children watch TV on Saturday or Sunday  evening. They are always busy with

their lessons. But a few children watch TV every night. They go to bed very late. They can't have a good

rest. That's too bad.

根据短文内容,补全句子.

1. Children like the________________ programs on TV.

2. They can get to know the world by______________ TV.

3. They like TV programs_____________ than radio programs.

4. They can learn more easily when they can hear  and watch at the____________ time.

5. There are some teaching programs on the____________,too.

6. TV helps to open_______________ children's eyes and their brains.

7. That's the  new_____________ of working out things.

8. With TVs and radios around us, the world is getting_________________.

9. Children can't watch TV for too long because they are always__________________ with their

lessons.

10.It is____________ for children to watch TV every  night.

下图示意某地区通过钻探某一岩层得出的地质数据：黑点代表钻井位置，斜线左边数据代表井口所在地面海拔高度（单位：米），斜线右边数据代表该岩层层顶的埋藏深度（即距离地面的垂直距离，单位：米），据此回答下列各题。

小题1:关于甲、乙、丙、丁四地的说法正确的是

A．甲地地形坡度在四地中最缓

B．乙地地貌的形成以外力为主

C．丙地地下为良好的储油构造

D．丁地地貌的形成以内力为主小题2:若该地区位于地中海沿岸，则降水最多的地点是

A．甲

B．乙

C．丙

D．戊

将pH值相同的盐酸和醋酸稀溶液，分别用蒸馏水稀释至原体积时m倍和n倍后，两溶液的pH值仍然相同，则m和n的关系是[ ]

A.m<n

B.m>n

C.m=n

D.无法确定

石材幕墙构架中的横梁应通过角码、销钉或螺栓与立柱连接，角码应能承受横梁的（）。

A、荷载

B、重量

C、剪力

D、弯矩

某投资方案建设期为2年，建设期内每年年初投资400万元，运营期每年年末净收益为150万元。若基准收益率为12%，运营期为18年，残值为0，并已知(P/A，12%，18)＝7.249 7，则该投资方案的净现值和静态投资回收期分别为( )。

A．213.80万元和7.33年

B．213.80万元和6.33年

C．109.77 万元和7.33年

D．109.77万元和6.33年