单项选择题：根据《中华人民共和国城乡规划法》，城乡规划组织编制机关应当委托具有( )资质等级的

题型：选择题

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题型：阅读理解

When you watch TV programs about wild animals, it is surprising to see how an antelope (羚羊) can run away from a strong lion. In the wilderness, everyone has his own way to protect himself. Even plants have their own ways to fight off enemies.

Over millions of years, plants have developed their own defense system (防卫系统). Chemicals are fantastically used by plants to survive (幸存). By making their leaves, flowers, roots and fruits poisonous (有毒的) to enemies, plants can fight back.

One such plant is the Golden Wattle tree. The British scientist David Cameron has found when an animal eats the tree’s leaves, the amount (数量) of poison increases in the other leaves. “It’s like the injured leaves telephoning the others to fight together against the enemy,” he said.

The tree also sends defense messages to neighboring plants by giving out a special smell. Golden Wattle trees in the nearby 45 meters will get the message and produce more poison within 10 minutes. Now, if an enemy eats too many of the trees’ leaves, he will die.

Every kind of plant or tree is good at producing a special set of chemicals. Herbivores, like rabbits, can safely eat the leaves of one tree, but they may be poisoned by its neighbor.

In this way, plants have not only developed their own defense system, but also shared it with others. This makes it impossible for a single animal to destroy even a small area of forest.

小题1:From the first 2 paragraphs, we can learn that _________.

A．plants can do nothing against their enemies

B．chemicals are quite useful for plants to survive

C．an antelope can always run away from a strong lion

D．leaves, roots, flowers and fruits of plants are poisonous小题2:If animals eat one Golden Wattle tree’s leaves, the tree can________.

A．kill the animals with a special smell

B．tell other trees to come to protect it

C．warn other trees against the animals on the phone

D．send defense messages to the neighboring plants小题3:The underlined word “herbivores” in the 5th paragraph probably means animals which _____.

A．produce poison

B．live on small animals

C．like to eat rabbits

D．feed on plants or grass小题4:The last paragraph of the passage suggests that this kind of defense system is ________.

A．bad for animals

B．good for forests

C．helpful to some animals

D．harmful to forests小题5:The passage is mainly about __________.

A．the examples of protecting forests

B．the balance between animals and plants

C．the ways of plants fighting against enemies

D．the relationship between lions and antelopes

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“伽利略”全球定位系统由我国和欧盟合作完成，其空间部分由平均分布在三个轨道上的30颗卫星组成，每个轨道上等间距部署10颗卫星，从而实现高精度的导航定位．假设“伽利略”全球定位系统中每颗卫星均绕地心做匀速圆周运动，轨道半径为r，某个轨道上10颗卫星某时刻所在位置如图所示，其中卫星1和卫星3分别位于轨道上的A、B两位置．若卫星均顺时针运行，地球表面处的重力加速度为g，地球半径为R，不计卫星间的相互作用力，则以下判断正确的是（　　）

A．这10颗卫星加速度的大小均为

B．这10颗卫星的运行速度大小为2R

C．这10颗卫星的运行速度一定大于7.9km/s

D．卫星1由位置A运动到位置B所需的时间为