我国有广袤的陆地、辽阔的海洋、复杂的地形和多样的气候，从而形成了_刷题宝

题干

我国有广袤的陆地、辽阔的海洋、复杂的地形和多样的气候，从而形成了（）

A：湖泊和海洋生态系统

B：森林和草原生态系统

C：城市和农田生态系统

D：以上三项都有

上一题下一题 0.0难度选择题更新时间:2019-12-28 08:46:51

答案(点此获取答案解析）

D

同类题1

下列对一些事实的解释中，不合理的是（　　）

同类题2

表示双曲线．则

同类题3

现在提倡使用的下列产品中，与环境保护无关的是（）

同类题4

如图，游客从某旅游景区的景点A处下山至C处有两种路径．一种是从A沿直线步行到C，另一种是先从A沿索道乘缆车到B，然后从B沿直线步行到C．现有甲、乙两位游客从A处下山，甲沿AC匀速步行，速度为50m/min．在甲出发2min后，乙从A乘缆车到B，在B处停留1min后，再从B匀速步行到C．假设缆车匀速直线运动的速度为130m/min，山路AC长为1260m，经测量，cosA=

\frac{12}{13}

\frac{3}{5}

同类题5

根据短文理解，从A、B、C、D四个选项中选择最佳答案填空。

Somebody says, “Time is money.” But I think time is 1 important than money. Why do I think so? Because when money is over, we can get it back. But when time is 2, it'll never be 3. That's 4 we shouldn't waste time.

It goes with saying that the 5 is usually limited（有限的）. Even a second（秒） is very important. We should make full use of our time to do 6 useful.

But a lot of people do not know the importance of time. It is a pity. They spend their limited time smoking, drinking, sleeping and 7. They do not know that wasting time means wasting part of their own 8.

In a word, we should save time. We shouldn't 9 today's work for tomorrow. Please remember that we have 10 time to waste.

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