题目内容：

    As a kid,I wanted to be a naturalist. When I got to college, I chose what I thought was a more practical path, studying physics along with public policy. That combination led me to atmospheric sciences. Now I'm studying low clouds.

But I didn't really notice low clouds until I started my study at the University of Washington, in Seattle. That city had a lot of low clouds. I suddenly realized how important their reflection of heat back into space was for Earth's climate. I continued studying how clouds at the University of Colorado in Boulder. There I earned my PhD.

Seattle's skies may be home to plenty of low clouds, but there are even better places to spot these little clouds. The greatest gatherings tend to occur off the coasts of places like Namibia, in Africa, and northern Chile. These places are home to some of Earth's driest deserts. And I like visiting such places.

The more I learned about these little clouds, the more fascinating I found them. I'm really interested in the various ways these low clouds respond to their environment. Because there are so many low clouds and they help keep Earth cool by reflecting(反射) heat, anything that affects them can also affect overall climate. It feeds back to the whole energy balance of the planet.

Lately I've been exploring how smoke that drifts(漂浮 )over clouds might change the way that these clouds absorb or reflect sunlight. Such smoke -from burning trees and grasses-can drift thousands of kilometers. If that smoke affects clouds, it might also affect climate. Last year, I spent a month on distant Ascension Island in the South Atlantic Ocean setting up instruments to track the interaction(相互作用) between low clouds there and smoke from southern Africa.

I appreciate the diversity in my work. Besides the occasional trip to distant islands, I also teach and work with other scientists to better understand Earth's climate system. Along the way, I'm helping bring one type of low clouds to the attention it deserves.

1.What do we know about the author?

A.She learned three majors at the same time in college.

B.She wanted to study low clouds when she was a kid

C.She knew the importance of low clouds when in university

D.She was always worried about climate change in the world

2.Why does the author like visiting places like Namibia and Northern Chile?

A.Because she enjoys views of deserts.

B.Because she loves visiting beautiful coasts.

C.Because she has got tired of Seattle's skies.

D.Because they're great places for observing low clouds.

3.What was the author's purpose in spending a month on Ascension Island?

A.To study smoke' s effect on low clouds

B.To find the real causes of climate change.

C.To set up instruments for other scientists

D.To study the influence of low clouds on climate.

4.What does the underlined word"diversity "in the last paragraph mean?

A.The fact of being very special B.The fact of working by oneself

C.The fact of being respected by others D.The fact of including some different things.