7．Arthur promised that he would answer the policeman's questions with honesty（誠(chéng)實(shí)）．

6．I regret that a previous（先前的）engagement prevents me from accepting your kind invitation．

5．Some people left Harry when hegot into trouble（陷入困境），but Joe stood by him all the time．（into）

4．Natural resources on the earth are very limited，so we should make good use of them and protect them．

3．A great number of people can get injured or even killed resulting from a human stampede（踩踏）．The bad thing is that a peaceful group of people can quickly turn into a crazy panicked crowd．（36）GIf you are in a crowd，the most important thing is to make yourself familiar with your surroundings and mentally notice the exits．No matter where you are，make sure you always know how to get out．（37）AIf you are in a crowd of moving people，wet or uneven ground can be slippery（滑溜的） or dangerous，causing you to fall．
Be aware of the general atmosphere of the event，as panic situations can often be expected．When in danger，a few seconds can make all the difference．If you find yourself in the middle of a moving crowd，do not fight against the pressure，do not stand still or sit down．（38）DTake advantage of any space that may open up and try to move sideways to the crowd movement where the flow is weaker．
（39）EIt gives you movement and protects your chest．
If you fall，get up quickly．If you fall and can not get up，keep moving by crawling in the same direction of the crowd，or if that is not possible，then cover your head with your arms and curl（蜷縮） up．（40）BSometimes，finding a right posture can save your life．

A．Make yourself aware of the type of ground you are standing on．
B．Do not lie on your stomach of back，as this dangerously exposes your lung．
C．If  you are stepped on，you should shout for help．
D．Instead，move in the same direction of the crowd．
E．Keep your hands up by your chest，like a boxer．
F．Stretch your arms to the full length so that you can make more space to move in the crowd．
G．What's worse is that the stampede can be caused while there seems no actual danger．

2．Think about the different ways that people use wind．You can use it to fly a kite or to sail a boat．Wind is one of our cleanest and richest power sources，as well as one of the oldest．Evidence shows that windmills（風(fēng)車） began to be used in ancient Iran back in the seventh century BC．They were first introduced to Europe during the 1100s，when armies returned from the Middle East with knowledge of using wind power．
For many centuries，people used windmills to grind（磨碎） wheat into flour or pump water from deep underground．When electricity was discovered in the late 1800s，people living in remote areas began to use them to produce electricity．This allowed them to have electric lights and radio．However，by the 19 40s when electricity was available to people in almost all areas of the United States，windmills were rarely used．
During the 1970s，people started becoming concerned about the pollution that is created when coal and gas are burned to produce electricity．People also realized that the supply of coal and gas would not last forever．Then，wind was rediscovered，though it means higher costs．Today，there is a global movement to supply more and more of our electricity through the use of wind．
28．From the text we know that windmillsC
A．have rarely been used since electricity was discovered
B．have a history of more than 2，800 years
C．used to supply power to radio in remote areas
D．were invented by European armies
29．What was a new use for wind power in the late 19gh century？C
A．Sailing a boat．
B．Grinding wheat into flour．
C．Producing electricity．
D．Pumping water from underground．
30．One of the reasons wind was rediscovered in the 1970s is thatB
A．it is one of the oldest power sources
B．wind power is cleaner 
C．it was cheaper to create energy from wind
D．the supply of coal and gas failed to meet needs
31．What would the author probably discuss in the paragraph that follows？
B
A．The adv antages of wind power．
B．The global trend towards producing power from wind．
C．The worldwide movement to save energy．
D．The design of wind power plants．

1．Thoughwarned（warn） of the danger，the children still went swimming in that pound．

20．I have sent her the invitation butwhethershe will accept it I don't know．

19．withher attention fixed on her book，she didn't notice her enter the room．

18．He promises to give the position towhoeverhe thinks is fit for it．