阅读理解：阅读下列短文，回答文后问题，选择最佳答案Robert had just moved into the street and he felt strange that he was not wanted. He knew that perhaps the other boys were trying to get an idea of what kind of a boy he was. This did not help him to make himself less lonely. He was new and he had to be tested. Still, proving himself would not be all that easy. He did not want to run with the boys or get into something against the law to prove that he was strong. No! He must show what he was made of in a more helpful way. That’s when he got the idea.The next day was Saturday. He knew that most of the boys would be down on the playground and choose up sides for the Saturday game. Robert knew he could play well and that just might be enough to prove he was strong, and to make friends with them. He arrived early and did his step exercises. He shot the ball several times and did some other exercises—the most difficult and most wonderful in basketball. Then the boys came. Robert went through what he had done before the game and showed what he could do. No one said a word. The boys just looked at each other and thought about it. In the end, when it was all over, the biggest of the group just smiled and shook his head. Robert knew he had made it.Which of the following is the best title for this passage?

Smile at everyone It doesn’t matter（ ） he or she is, and that will help you to grow up in greater love for each other.

After so many years, he still ____ the hope that his lost son would return one day.

There is no one of us but wishes to go swimming in the lake.

Trees mainly serve man in three important ways: They provide him with wood and other products; they provide him shade; and they help to prevent droughts and floods.Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important．In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear.This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind(固定) the soil, thus preventing it from being washed away easily；but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert.Two thousand years ago，a rich and powerful country cut down its trees to build warships, with which to gain itself an empire．It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation(饥荒)．Which title best fits the passage?

Latin America has an __________ labor force and natural resources.

阅读理解：阅读下列短文，回答文后问题，选择最佳答案Robert had just moved into the street and he felt strange that he was not wanted. He knew that perhaps the other boys were trying to get an idea of what kind of a boy he was. This did not help him to make himself less lonely. He was new and he had to be tested. Still, proving himself would not be all that easy. He did not want to run with the boys or get into something against the law to prove that he was strong. No! He must show what he was made of in a more helpful way. That’s when he got the idea.The next day was Saturday. He knew that most of the boys would be down on the playground and choose up sides for the Saturday game. Robert knew he could play well and that just might be enough to prove he was strong, and to make friends with them. He arrived early and did his step exercises. He shot the ball several times and did some other exercises—the most difficult and most wonderful in basketball. Then the boys came. Robert went through what he had done before the game and showed what he could do. No one said a word. The boys just looked at each other and thought about it. In the end, when it was all over, the biggest of the group just smiled and shook his head. Robert knew he had made it.1.What does “This did not help to make him less lonely” mean?

判断线上的内容是否正确：These two chemicals ____interact_____ with each other at a certain temperature to produce a substance which could cause an explosion.

阅读理解：阅读下列短文，回答文后问题，选择最佳答案Trees mainly serve man in three important ways: They provide him with wood and other products; they provide him shade; and they help to prevent droughts and floods.Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important．In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear.This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind(固定) the soil, thus preventing it from being washed away easily；but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert.Two thousand years ago，a rich and powerful country cut down its trees to build warships, with which to gain itself an empire．It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation(饥荒)．1. According to the passage, which is the most important service of trees to man?

阅读理解：阅读下列短文，回答文后问题，选择最佳答案Trees mainly serve man in three important ways: They provide him with wood and other products; they provide him shade; and they help to prevent droughts and floods.Unfortunately, in many parts of the world, man has not realized that the third of these services is the most important．In his eagerness to make money from trees, he has cut them down in large numbers, only to find that without them he has lost the best friends he had. And besides, he is usually too careless to plant and look after new trees. So the forests slowly disappear.This does not only mean that man will have fewer trees. The results are even more serious: for where there are trees, their roots break up soil allowing the rain to sink in and also bind(固定) the soil, thus preventing it from being washed away easily；but where there are no trees, the rain falls on hard ground and flows away, causing floods and carrying away the rich top-soil. When the top-soil is gone, nothing remains but worthless desert.Two thousand years ago，a rich and powerful country cut down its trees to build warships, with which to gain itself an empire．It set up the empire, but, without its trees, its soil became poor and grew weak. When the empire fell to pieces, the home country found itself faced by floods and starvation(饥荒)．2. In many places forests slowly disappear because __________.