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问题 选择题

一瓶固体经化验只含有一种元素，则该固体是（　　）

A．一种单质

B．单质与化合物的混合物

C．一种化合物

D．既可能是一种单质，也可能是混合物

答案

A、不一定是单质，如金刚石和石墨的混合物，故A错误．

B、化合物至少两种元素，但该固体只有一种元素，不可能是单质与化合物的混合物；故B错误．

C、化合物至少两种元素，但该固体只有一种元素，不可能是化合物，故C错误．

D、若为纯净物时，该固体为单质；也可能为单质组成的混合物．故D正确．

故选D．

多项选择题

在财产清查过程中形成的下列资料中，可以作为原始凭证的有（）。

A.库存现金盘点报告表

B.银行存款余额调节表

C.实存账存对比表

D.正在报批中的往来款项清理结果报告表
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单项选择题

A balanced diet provides an adequate intake of nutrients for maintenance of the body and therefore good health. A diet can easily be adequate (67) normal body functions, yet may not be a balanced diet. An ideal human diet (68) fat, protein, and carbohydrates (碳水化合物) in correct (69) . The exact amount vary for each (70) because everyone has different metabolic (新陈代谢的) rates and levels of activity. Malnutrition results (71) an unbalanced diet, this is (72) an excess of some dietary components and (73) of other components. Too much of one component can be as much (74) to the body as too little. Energy is (75) by carbohydrates, fats and proteins. Proteins are primarily used as building blocks for (76) of many body tissues. The energy providing compounds are needed in (77) quantities in our diet. We also need much smaller amounts of other nutrients, such as vitamins and minerals. (78) the small quantities needed these are essential to provide a healthy diet as they have (79) roles in metabolic reactions. The (80) absorbed are converted to other compounds which are then used for metabolism. Starch, a major carbohydrate, can be then synthesized into fat for (81) . There are some organic compounds which in spite of being (82) for health cannot be made by cells. A balanced diet is imperative to (83) a healthy body. People who choose to be vegetarians and (84) must make sure that their diet contains all the correct nutrients to (85) any deficiencies. This is the same for people living in countries (86) their diet lacks certain important food groups.

A．therefore

B．notwithstanding

C．however

D．furthermore
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