下列各组离子中在水溶液中能大量共存的是（） A．Fe2+、K+、ClO—、Cl—

供货方进度计划应包括供货的______等所有环节。

A．运输

B．保险

C．投标

D．仓储

在填筑排水反滤层过程中，每层在25mX25m的面积内取样1-2个，地条形反滤层，每隔( )设一取样断面，均匀分布在断面的不同部位，且层间取样位置应彼此对应。

A．30m

B．50m

C．60m

D．80m

以下是一组有关我国农业问题的材料：

材料1
　　　　　　　 　 　我国农村经济近年来的发展情况

年度	1996	1997	1998	1999
粮食总产量(公斤)	4800亿	4925亿	4900亿	5080亿
农民收入增幅	9%	4.6%	4.3%	3.8%

注：从1978年到1998年，20年中我国农民人均纯收入由134元增加到2162元，年均递增近8%。1999年农民人元气纯收入2210元，比上年增幅减少0.5个百分点。
材料2 我国农民纯收入的60%来自种养业。据测算，每1元产品，通过储藏、保鲜、加工处理，美国可增殖3.72元，日本为2.2元，我国只有0.38元。近几年，我国粮食连年丰收，许多粮仓爆满，市场上的粮食价格持续走低。虽然我国现在也出口玉米、大米等具有比较优势的粮食，但由于国内生产的粮食品种、质量还不能满足经常变化的市场的需求，所以还要进口生产高档面包、糕点的专用小麦等粮食。加上结构单一，往往增产而不能增收。
材料3 据报道，素有“冀东粮仓”之称的河北省乐亭县，农业人口达96%，过去单一的粮棉种植结构导致了“高产穷县”。1991年，他们调整了农业结构，构筑了“西菜东果南部粮，沿海水产遍地养”的格局，全县粮食作物和经济作物的比例由90年代初的7：3，调整为现在的5：5，全县的果品、蔬菜、珍稀皮毛动物饲养三大主导产业都有了很大发展。去年全县人均收入的3479元中，果菜收入就占了63%。
结合上述材料，请回答：
(1)上述三则材料各反映了什么经济现象
(2)结合材料2、3，谈谈你对实现我国农业发展和农民增收的认识。

The following two questions are based on the following passage:

A study by a group of dentists has concluded that regular use of a certain brand of mouthwash is as effective as flossing in preventing gum disease. The mouthwash company has released a television ad suggesting that people who do not like flossing can now rely solely on mouthwash and brushing to maintain good dental health. A leading manufacturer of dental floss brought a lawsuit against the mouthwash company demanding that the advertisement be discontinued on the grounds that it is misleading.

Which of the following, if true, provides the pest support for the dental floss company’s claim that the advertisement is misleading ？（）

A. The dental floss manufacturer is concerned that it will lose market share in the dental health market because the advertisement encourages people to switch from dental floss to mouthwash.

B. The dental floss company claims in its own advertisements that brushing and flossing after every meal is the most effective way to maintain good dental health.

C. Although mouthwash is an effective deterrent to gum disease, it is less effective than dental floss at removing plaque and preventing cavities between teeth.

D. Per usage, mouthwash is three times more expensive than dental floss, if the recommended amounts of both products are used.

E. The dentists who conducted the study on the effectiveness of mouthwash in preventing gum disease obtained their funding for the study from a company that manufactures mouthwash.

本质安全型设备就是质量可靠的设备。（）