if someone asked you, what color is the sky? i expect that you would answer, blue. i am afraid that you would be wrong. the sky has no color. when we see blue, we are looking at blue sunlight. the sunlight is shining on little bits of dust in the air.
what is the sky? the sky is space. in this space there is nothing except the sun, the moon and all the stars.
the moon is about 384,000 kilometers away from the earth. an airplane cannot fly to the that can fly even when there is no air. this is rocket.
this is how a rocket works. it is not made of rubber like a balloon, of course. it is made of metal. the metal must not be heavy but it must be very strong. there is gas inside the rocket which is made very hot. when it rushes out of the end of the rocket, the rocket is pushed up into the air.
练习:
a) it is blue.
c) it is grey.
2. when an airplane flies too high,
b) the air will become thicker.
d) the air will disappear in no time.
a) it looks like a balloon.
c) it doesnt have wings.
4. which of the following statements about a rocket is not true?
b) it can fly without wings.
d) it is propelled by burning gas inside it.
a) hot gas rushes out of its head.
c) hot gas rushes out of its bottom.
答案:daddc
大学英语四级词汇:写作常用词组精编(六)
大学英语四级词汇高频词汇5
搞定四级:同根同缀词汇记忆法
英语四级考试历年常考高频词汇:经济类
10天搞定大学英语四级核心词汇:day1
英语四级词汇训练营:四级听力60个高频词组
10天搞定大学英语四级核心词汇:day7
英语四级考试考点词汇及真题解析
英语四级高频词汇:表示目的与结果的连接词
英语四级高频词汇:表示次序与因果的连接词
英语四级高频词汇:表示比较与对照的连接词
英语四级考试历年常考高频词汇:灾难类
10天搞定大学英语四级核心词汇:Day4
历年英语四级考试词汇选择部分15
大学英语四级词汇:写作常用词组精编(三)
英语四级考试历年常考高频词汇:人及性格
大学英语四级词汇高频词汇2
大学英语四级考试常见连接词总结
10天搞定大学英语四级核心词汇:day10
大学英语四级词汇高频词汇4
过关者必备:英语四级最常考的一百个短语
10天搞定大学英语四级核心词汇:Day3
英语四级高频词汇:表示条件与地点的连接词
英语四级考试历年常考高频词汇:工作类
英语四级词汇突击 高频必备top690
英语四级考试历年常考高频词汇:情感类
10天搞定大学英语四级核心词汇:day8
10天搞定大学英语四级核心词汇:Day 2
10天搞定大学英语四级核心词汇:day6
10天搞定大学英语四级核心词汇:day9
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |