现在流行性脑脊髓膜炎的发病率大幅度下降，呈现A．散发 B．爆发 C．流行 D．大流行

井下巷道内的电缆，沿线每隔一定距离，拐弯或分支点以及连接不同直径电缆的接线盒两端，穿墙电缆的墙的两边都应设置注有（）的标志牌。

A、编号、用途

B、电流大小

C、电压和截面

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

世界上各种原油的性质虽然差别甚远，但基本上由五种元素即碳、氢、硫、氮、氧所组成。

朱砂主要毒性成分是

A．乌头碱
B．士的宁
C．强心配糖体
D．二硫化二砷
E．汞

社会主义初级阶段的历史任务是（）。

A.实现社会主义现代化

B.实现工业化和经济的社会化、市场化、现代化

C.在社会主义基础上实现中 * * 伟大复兴

D.实现小康

E.达到中等发达国家水平