确诊最有价值的辅助检查是A．超声波检查 B．排泄性尿路造影 C．放射性核素肾图 D．

一列简谐横波沿x轴传播，周期为T。t=0时刻的波形如图所示，此时平衡位置位于x=3 m处的质点正在向上运动，若a、b两质点平衡位置的坐标分别为x_a=2.5m，x_b=5.5 m，则

A．当a质点处在波峰时，b质点恰在波谷

B．t=T/4时，a质点正在向y轴负方向运动

C．t=3T/4时，b质点正在向y轴负方向运动

D．在某一时刻，a、b两质点的位移和速度可能相同

以下关于程序测试的叙述，正确的是______。

A．程序测试的目的是为了证明程序的正确性

B．白盒测试也称为功能测试

C．黑盒测试也称为结构测试

D．程序测试要注意检验程序是否有多余的功能

马克思主义揭示人的本质出发点是

A．人的自身需要

B．人类的共同利益

C．人的自然属性

D．人的社会关系

胎儿体内无纯动脉血。()

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 is implied in the passage().

A. The White House disappoints its funders by refusing to give them heavy preference they expected.

B. Financial supporters in presidential election can always be rewarded by an important position in the government.

C. Participation in the Commerce Secretary’s trade missions abroad might bring donors abundant rewards.

D. Financial contributors in presidential election are inevitably clearly recorded in Commerce Department documents.