问题 选择题

潜水员潜入水中工作时看见岸上树梢位置变高了。在如图所示的四幅光路图中,能正确说明产 生这一现象原因的是     

答案

答案:B

题目分析:潜水员潜入水中看岸上的树梢时,光是从空气射入水中,当光由从空气射入水中时折射光线靠近法线,折射角小于入射角,潜水员逆着折射光线看到的是树梢的虚像。故选B

问答题
单项选择题

For any export-oriented American business, an invitation to join the U. S. Commerce Secretary on one of his trade missions abroad is like a World Series ticket—the hottest seat in town, and something you might pay top dollar to get. In 1992, Bill Clinton promised that his Administration would fight hard to help American companies win foreign business. That’s a worthy goal of trade missions, which provide selected chief executives with priceless connections to the corporate heads and government officials of other nations.

But under the late Commerce Secretary Ron Brown were the Democrats "selling" seats, using those missions to reward party donors And did the trips serve the dual purpose of drumming up (招徕) more donations abroad Those are the questions at the heart of the lawsuit filed by the non-profit conservative group Judicial Watch Inc. Last week, thousands of pages of Commerce Department documents have been turned over to the group.

The Commerce Department papers clearly indicate many corporate contributors expected their money to earn them special consideration when seats were being handed out on the secretary’s plane. In a letter addressed to Deputy Assistant Commerce Secretary Jude Kearney, C. Payne Lucas, a development-organization executive suggests he should be added to a mission headed for South Africa president Nelson Mandela. In another, Philip Verveer, a Washington attorney, recommends a place on 1994 mission to India for William Ginsberg, chief executive of Cellular Communications International. "Oinsberg was an early financial supporter of Clinton/ Gore campaign," Verveer writes.

These missives occasionally show federal officials urging their superiors to favor donor executives. In one letter, Reta Lewis, a political affair official at the White House, urges that a spot be found for Gerald McGowan, a partner in a Washington law firm, on a trade mission to Indonesia or India. For one thing, Lewis points out, McGowan qualifies as D. N. C. "managing trustee (托管人, 理事)," someone who gives $100,000 a year to the Democratic National Committee.

But did the White House always give its funders the heavy preference they expected That is another story.

Which of the following statements is true().

A. Clinton’s Administration failed to keep his promise to help American companies win foreign business.

B. The Democrats might have taken advantage of the trade trips for more donations abroad.

C. Donor Executives long to have the honor of taking the same plane as the Commerce Secretary.

D. The Commerce Department documents clearly indicate that corporate contributors hope to finance the Secretary’s missions abroad.