Metal plates that cover the top of the hawsepipe are called（）.

A . right B . wrong C . not mention

A . Limited in a single building, a group of buildings, or even a single room B . Crosses metropolitan, regional, or national boundaries C . Encompasses an entire city or metropolitan area and connects multiple local-area networks (LANs) D . Connects client devices wireless protocol

A . comprehensive B . integrated C . redundant D . productive

A . cirrus B . cirrostratus C . altostratus D . cirrocumulu

A . compound plate B . furnaced plate C . flat plate D . rolled plate

A.Cirrus B.Cirrostratus C.Altostratus D.Cirrocumulus

A.nations which send sailors around the globe will be stronger B.nations which develop physics and astronomy will be stronger C.nations which support science exploration will be stronger D.nations which dominate the world will be stronger

A．freight B．cost C．insurance D．voyage

A. 要提供职位广告里具体要求的任何信息，你的简历里没有包括。 B. 要提供具体信息，这是招聘广告要求，也是简历里没有的。 C. 要提供简历里可能未包括而招聘广告里又特别要求的信息。

是 否

A．A.melt B．B.must melt C．C.would melt D．D.had melted

A penetrated B occupied C invaded D entered

A．Using of B．Writing on C．Reporting by D．According to

David Salt is an expert on plants at Purdue University in West Lafayette, Indiana. He is working with plants that store large amounts of metals. In recent years, scientists have shown interest in using such plants to clean up harmful waste materials. Professor Salt says such plants also could be used to improve people's diets or even to create foods that fight cancer. Humans need a number of metals in their diets, including iron and zinc. These metals are needed in very small amounts, however. That is why they are called micronutrients. The lack of micronutrients is blamed for health problems in many developing countries. Children and pregnant women are mostly affected. Recently, Mr. Salt announced that he has identified and copied the genes from a kind of plant that stores metals in its tissues. He says his study suggests it may be possible to develop plants that contain minerals needed for good health. For example, the metal selenium is a strong anti-cancer agent. Some wild plants store selenium naturally. Mr. Salt says foods to fight cancer might be created if genes from these plants could be moved into crop plants. Locoweed, which is a common plant in the western U.S., stores selenium. Professor Salt says it may be possible to create cancer-fighting foods from it. He and scientists from a company called Unicycle Therapies have copied the gene that causes locoweed to take up selenium from the soil. Many people take pills to add important minerals or vitamins to their diet. However, Mister Salt notes that most selenium products sold in health food stores are of little use. That is because the human body can only take in and use selenium if it is in the right chemical form. The scientist says his team would like to develop a vegetable crop high in selenium. He wants to create an anti-cancer product in the foods we already eat. According to Pro. Salt, plants that take up large amounts of metal in their tissues can be used to ______. A．clean polluted soil and cure disease like cancer B．clean up harmful waste materials in soil and improve people's diet C．produce large number of micronutrients such as iron and zinc D．create food with important minerals or vitamins

A．increasing marginal utility． B．diminishing marginal utility． C．diminishing total utility． D．the paradox of valu E．

A．A.More cost B．B.More density C．C.Less cost D．D.Less density