【单选题】Mothers and matchmakers(媒人) have always known that not being married is a definite health hazard. But when a team of researchers from the University of California, San Francisco, reported a few weeks ...
【简答题】The author considers it impossible to obtain no-risk food because ________. A) no food is free from pollution in the environment B) pesticides are widely used in agriculture C) many vegetables contain...
【简答题】It was a very foggy day in London. The fog was so thick that it was impossible to see more than a foot or so. Buses, cars and taxis were not able to run and were standing by the side of the road. Peop...