Astronomy is the oldest science known to man. Thousands of y

助动词?可以没有的啊

第一个,考察的是名词性从句 由what引导.再根据意思可只要选的little.
第二个,考察的是定语从句的连接词故选D,至于C答案首先不完整应该再加上is再一个是它放到句子里头后面也没法连接.
第三个,前面整体是主语部分,所以需要个谓语和表语部分,D答案刚好符合that引导表语从句.
第四个,答案应该就是C原因说不上来,只凭语感.

知道光谱学发展的今天,天文学才真正繁荣发展为科学

Li Hua gets the hange of astronomy.He is puzzled what exists in our sdar system.What dissatisfied him is that books can only tell him theoretical knowledge.In 2012,successful launch of Shenzhou9 cheered him up.As astronauts can be sent to the space,they will go to space themselves sooner or later.

3道题都是同位语从句题 同位语从句由that引导 用于解释that前面的名词
而且that后的从句是一个完整的句子,即主谓宾等都会有
答案就很明显了 分别是 D B C

B

A

HOW LIFE BEGAN ON THE EARTH
No one knows exactly how the earth began,as it happened so long ago.However,according to a widely accepted theory,the universe began with a "Big Bang" that threw matter in all directions.After that,atoms began to form and combine to create stars and other bodies.
For several billion years after the "Big Bang",the earth was still just a cloud of dust.What it was to become was uncertain until between 4.5 and 3.8 billion years ago when
the dust settled into a solid globe.The earth became so violent that it was not clear whether the shape would last or not.It exploded loudly with fire and rock.They were in
time to produce carbon,nitrogen,water vapour and other gases,which were to make the earth's atmosphere.What is even more important is that as the earth cooled down,water
began to appear on its surface.
Water had also appeared on other planets like Mars but,unlike the earth,it had disappeared later.It was not immediately obvious that water was to be fundamental to the development of life.What many scientists believe is that the continued presence of water allowed the earth to dissolve harmful gases and acids into the oceans and seas.This produced a chain reaction,which made it possible for life to develop.
Many millions of years later,the first extremely small plants began to appear on the surface of the water.They multiplied and filled the oceans and seas with oxygen,which encouraged the later development of early shellfish and all sorts of fish.Next,green plants began to grow on land.They were followed in time by land animals.Some were insects.Others,called amphibians,were able to live on land as well as in the water.Later when the plants grew into forests,reptiles appeared for the first time.They produced young enerally by laying eggs.After that,some huge animals,called dinosaurs,developed.They laid eggs too and existed on the earth for more than 140 million years.However,
65 million years ago the age of the dinosaurs ended.Why they suddenly disappeared still remains a mystery.This disappearance made possible the rise of mammals on the earth.These animals were different from all life forms in the past,because they gave birth to young baby animals and produced milk to feed them.
Finally about 2.6 million years ago some small clever animals,now with hands and feet,appeared and spread all over the earth.Thus they have,in their turn,become the most important animals on the planet.But they are not looking after the earth very well.They are putting too much carbon dioxide into the atmosphere,which prevents heat from escaping from the earth into space.As a result of this,many scientists believe the earth may become too hot to live on.So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.

天文是人类所知的最古老的科学.

你对天文学的什么感兴趣?你知道天文学家感兴趣的问题吗?

在某方面某领域应该用介词in,is是be动词,“是”的意思
如果帮到你,请记得采纳,O(∩_∩)O谢谢

助动词?可以没有的啊

新概念英语第三册
Lesson 55

through?
经过每年观察和计算的现代天文学

later
true
题干是studied 不能用make