Question

【题目】No one knows exact 【1】 the earth began, as it happened so long ago. 【2】 , according to a 【3】 (wide) accepted theory, the universe began with a “Big Bang” that threw matter 【4】 all directions. After that, atoms began to form and combine to create stars and other bodies.

Water 【5】 (appear) on other planets like Mars but, unlike the earth, it had disappeared later. 【6】 was not immediately obvious that water was to be fundamental to the development of life. What many scientists believe is that the continued 【7】 (present) of water allowed the earth 【8】 (dissolve) harmful gases and acids into the oceans and seas. This produced 【9】 chain reaction, 【10】 made it possible for life to develop.

Answer 1

【答案】

【1】how

【2】However

【3】widely

【4】in

【5】 had appeared

【6】It

【7】 presence

【8】to dissolve

【9】 a

【10】which

【解析】

试题分析：文章讲述了地球最初形成时期的一些现象及逐渐变化的过程。

【1】how 考查连词。没有人知道地球是如何开始形成的

【2】However 考查连词。此处前后之间是转折关系，故填However。

【3】widely 考查副词。此处用副词修饰动词accept，故填widely。

【4】in 考查介词。in all directions，四处; 四面八方，固定搭配。

【5】 had appeared 考查时态。根据后一句的时态可以确定此处为过去完成时，故填had appeared。

【6】It 考查代词。此处为形式主语，后面that做真正的主语，故用it.

【7】 presence 考查名词。此处意为水的存在，用名词，填presence。

【8】to dissolve 考查非谓语动词。此处为固定搭配，allow sb to do：允许某人做某事。

【9】 a 考查冠词。此处是泛指，一种连锁反应，填a。

【10】which 考查引导词。此处为非限制性定语从句，指代前面整个句子，做主语，故用which。