问题 选择题

对黄土高原的综合治理,措施不得力的一项是(  )

A.植树种草

B.建梯田、修挡土坝

C.退耕还林、还草

D.挖坎儿井引黄河水灌溉农田

答案

A.植树种草是综合治理黄土高原的根本措施之一,属于合理措施;

B.在坡度较缓的地方修梯田,可以减缓坡度;打坝淤地可使大量的肥土淤泥,在坝内变成沟底平地,既可拦水,淤泥又形成平坦肥沃的可耕地,一举两得,所以属于合理措施;

C.退耕还林、还草,加快林地建设,可以调节地面径流,属于合理措施;

D.坎儿井是荒漠地区一特殊灌溉系统,普遍于中国新疆吐鲁番地区,故属于不合理措施.

故选:D.

阅读理解

What do you do if you're in trouble on a lonely island? Surely you need to find a way to get in touch with the outside world. Your best chance of doing this is to draw the attention of a passing plane.

Body signals (信号)

Pilots from different countries understand body signals if they have the correct training, When you wave your arms up and down in a straight line, it means, "yes". When you point downwards and swing your arm from side to side, it means "no". If you want the pilot to know that it's safe to land, push your hands out in front of you and bend (弯曲) your knees. If you want to say that it's not safe to land, put your arms in the air and move them to one side.

Smoke signals

The smoke from a fire can be seen from far away, so it’s a good way to draw attention. If the weather is dry, it isn’t hard to start a fire. Remember, however, that fires can be very dangerous if they get out of control. Never light a tire unless you're sure that it can’t spread. If the ground is dark, light smoke can be seen more easily. Green grass and leaves produce light smoke.

Ground-to-air signals

It's a good idea lo build some signals, too. Use large pieces of wood to make the symbols (标记). If you can't find any wood, use earth. Some useful symbols are:

F "I need food and water"

II "I need medicine."

I "I am badly hurt."

X "I am unable lo move from here."

Pilots' replies

If the pilot lowers the plane's wings from side to side, this means: "message received and understood" (At night, the pilot flashes the plane's green lights.) If the pilot flies the plane in a clockwise circle, this means "message received hut not understood" (At night, the: pilot flashes the plants red lights.)

However, there is no signal which means "message not received. Why not'?

小题1:How many signals can we use to draw the attention of the passing plane if you're in trouble?

A.Three.

B.Four

C.Five

D.Six小题2:Which picture means "it's not safe to land"?

小题3:What can we learn from the passage?

A. Swinging your arm from side to side means "yes"

B. If the ground is dark, light smoke can’t be seen.

C If you need some medicine, make a symbol “Ⅱ”.

D. The pilots make replies with a blue light at night.

小题4:What is the passage mainly about?

A.The explanation of building signals on an island.

B.The importance of making signals on an island.

C.Ways of sending out signals on a lonely island.

D.Ways of receiving signals from a lonely island.

填空题