题目内容：

Paul Salopek is an old-fashioned explorer, setting out on foot to circle the world. He is also a modern-day explorer. On top of a few clothes, a small first-aid kit and notebooks, he is carrying a recorder, a video camera, a small computer and a satellite phone—a telephone that connects to a satellite and can be used in many places where cell-phones don’t work.

The journey is long 21,000 miles! It will take seven years to complete it.

Salopek was born in California and spent his childhood in Mexico. He says he has always liked to travel and doesn’t like to rush. At the age of fourteen, he climbed Moun. Whitney in California and crossed the state’s Sierra Nevada Mountains alone. When he was fifteen years, he walked the length of Death Valley. He once rode a mule 2,000 miles through mountains in Mexico.

A longtime reporter, Salopek has reported from Africa, Asia and Mexico. Now 51 years old, he plans to keep writing. As he travels around the world, he is writing stories about the people he meets and the way they live. He looks for how people find local solutions to big problems such as lack of food and water. He also records the sounds he hears and takes photos of the sky and the Earth’s surface.

The long walk started in the Rife Valley in Ethiopia in East Africa. Many consider East Africa to be home to the first humans, who lived 160,000 years ago.

Salopek is retracing the paths our ancestors took as they left Africa and settled in parts of the Middle East, Europe, Asia and the Americas. As Salopek is walking, he is learning more about himself and all of humankind.

1.The underlined phrase “on top of” in the first paragraph can be replaced by ____.

A.in addition to     B.in the light of

C.in reference to    D.in the service of

2.The author develops the third paragraph mainly by ____.

A.providing examples

B.making comparisons

C.making a careful analysis

D.following the order of time

3.According to the passage, Paul Salopek is a ____.

A.doctor who likes carrying the small first-aid kit

B.writer who likes traveling, exploring and studying

C.journalist who likes traveling, exploring, writing and studying

D.photographer who is good at using satellite communication equipment

4.What’s the best title for the passage?

A.Paul Salopek Reflecting People’s Real Lives

B.Paul Salopek Following Man’s First Footsteps

C.Paul Salopek Going for a Seven-year Study

D.Paul Salopek Looking back upon the Childhood