题目内容
Every one knows the (important)______ of learning a foreign language.
查看答案
搜索结果不匹配？点我反馈
更多问题
Section ADirections: This section is to test your ability to give proper responses. There are 5 recorded questions in it. After each question, there is a pause. The questions will be spoken two times. When you hear a question, you should decide on the correct answer from the 4 choices marked A, B, C and D given in your test paper. Then you should mark the corresponding letter on the Answer Sheet with a single line through the center.
We know that oxygen is necessary for the breathing of animals and plants and for burning. Only one-fifth of air holds oxygen, but this is quite enough for all ordinary uses. Pure oxygen is used for special kinds of breathing and burning, for instance, patients in hospital and research workers working in high mountainous district. High up about the earth air is not so plentiful. On the top of a mountain our lungs would not take in as much oxygen at each breath as they would at the bottom, and on very high mountains, breathing is so difficult that men have little strength. Air has enough oxygen for the burning of a fire. Pure oxygen would cause the wood or coal to burn so fast that it would be wasted. When a very hot fire is needed for a special purpose, oxygen is supplied instead of air. ______ cannot live without oxygen.
Section ADirections: This section is to test your ability to give proper responses. There are 5 recorded questions in it. After each question, there is a pause. The questions will be spoken two times. When you hear a question, you should decide on the correct answer from the 4 choices marked A, B, C and D given in your test paper. Then you should mark the corresponding letter on the Answer Sheet with a single line through the center.
I would like to thank you for you short but clear (explain) ______ .
微信支付 
支付宝支付