10．They made a lot of ________ (achieve) in astronomy.

　　解析：a lot of 后跟复数名词，achievements 成就。

　　答案：achievements

　　Ⅲ.语法填空

　　A: Over the past few months I __1__ (do) research on solar cars.

　　B: What is a solar car?

　　A: Solar cars are cars __2__ use the sun's energy for power. That means they don't use petrol, gas or any other fuel, just the sunlight.

　　B: And why are people __3__ (interest) in solar cars?

　　A: People have been worried about pollution __4__ (cause) by fuels such __5__ petrol and gas for a long time now. Solar cars are clean and safe.

　　B: You __6__ (work) on solar cars for a long time.

　　A: Yes. I __7__ (design) six different cars so far. I want people to have a good __8__ (impress) of solar cars.

　　B: But a lot of people think solar cars are not very __9__ (rely)．

　　A: Solar cars are getting better all the time. They can function well even in __10__ (cloud) weather.

　　答案与解析

　　1．have been doing　over the past few months 与现在完成进行时连用。

　　2．that/which　先行词为物，定语从句中缺主语，故用 that/which 引导。

　　3．interested　be interested in 对......感兴趣。

　　4．caused　pollution 与 cause 之间为被动关系，故用过去分词形式作定语。

5．as　such as 例如。