题目内容：

    Somewhere between 40,000 and 110,000 tons of plastic waste produced by Americans ends up in the ocean, according to a study published in the journal Science.

It's difficult to point out where all that waste comes from, and researchers think that much or most of it probably comes from the nation's seriously-populated coasts. But there's also evidence that the nation's inland waterways serve as a passage for plastic to travel thousands of miles into the oceans.

While researchers have documented plastic and human trash floating in the world's oceans, there has been relatively little attention paid to plastics in rivers, streams and lakes. "To my knowledge, no one has studied particular routes, with the exception of places like L.A, and Baltimore Harbor where there are measures in place to prevent trash in rivers from entering the ocean." said Kara Lavender Law, an oceanographer.

The few studies that exist, however, suggest that it may be a huge problem. A 2011 study of two southern California urban rivers---including Santa Ana River---found that every square meter of water contained from 125 to 819 pieces larger than 4.75 millimeters. Another survey of the Meuse River, which flows 575 miles through France, Belgium and the Netherlands to the North Sea, found that it contained 70,000 pieces of plastics per square meter of water, about 500 of which were roughly an inch or bigger in size.

If there's anything positive in this, it's you that can do something, at least on a personal level, to reduce the amount of plastic that goes into the oceans. "Put trash where it goes." said Jenna Jambeck, an associate professor of environmental engineering at the University of Georgia. "Use reusable items---bags, cups and bottles---to reduce waste."

Finally, Jambeck urges people to pick up litter along waterways, and record it with a phone app called the Marine Debris Tracker. The data you provide can help scientists to get a better handle on the trash problem.

1.According to the text, the least polluted place might be __________.

A.Santa Ana River B.Meuse River

C.Baltimore Harbor D.The North Sea

2.How does the author prove plastic waste in rivers is a huge problem?

A.By referring to experts' views. B.By listing statistics.

C.By making comparisons. D.By following time order.

3.What does Jenna Jambeck advise us to do?

A.Make use of plastic items. B.Reduce the size of waste we throw away.

C.Stay positive about the oceans' future. D.Start from small things to deal with waste.