平时结汇时按照当时的即时市场汇率核销应收、应付外汇账款，月末再将原币余额按照当日即期

       1821年，德国物理学家塞贝克发现了一种奇怪的现象：把两根铜丝和一根铁丝与灵敏电流计串联成闭合电路，然后把铜丝和铁丝的一个连接点放在盛有冰水混合物的容器里保持低温：另一个连接点放在火焰上加热。发现灵敏电流计的指针发生丁偏转，这一现象表明这时闭台电路中产生了电流。塞贝克把这种电流叫做“热电流”。把这一电路叫“热电偶电路”。 

      某研究小组的同学们按如图所示的电路，模拟塞贝克实验，探究了决定“热电流”大小的因素。通过实验测得了电流的大小与温差关系的一组数据：

请根据以上资料数据说明： （1）产生热电流的条件是___________             ；（2）根据热电流的特点，猜想并写出热电偶电路的一种应用：___________

男，50岁。发热、面色苍白2个月。骨髓细胞学检查示原始细胞占有核细胞的50%。细胞免疫表型检查结果：CD13⁺、CD14⁺、CD15⁺、CD33⁺。最可能的诊断是（）。

A.B-ALL

B.T-ALL

C.AML-M₂

D.AM-M₅

E.AML-M₇

The United States government publishes guidelines for appropriate nutrient intakes. These are known as the Recommended Dietary Allowances (RDAs) and are updated regularly based on new research in nutrition. RDAs are suggested amounts of calories, protein, and some minerals and vitamins for an adequate diet. For other dietary substances, specific goals must await further research. However, for the U.S. population as a whole, increasing starch and fiber in one’s diet and reducing calories (primarily from fats. sugar, and alcohol) is sensible. These suggestions are especially appropriate for people who have other factors for chronic diseases due to family history of obesity, premature heart disease, diabetes, high blood pressure, and high blood cholesterol, or for those who use tobacco. Snacks can furnish about one-fourth of the calorie requirements among teenagers. Those snacks should also provide much of the day’s allowances for protein, minerals, and vitamins. Sandwiches, fruit, and milk make good snacks for active teenagers. Food from the food pyramid may be part of any meal. A grilled cheese sandwich or a bowl of whole-grain cereal is just as nutritious in the morning as it is at noon. In addition, a good breakfast consists of any foods that supply about one-fourth of the necessary nutrients for the day.

The passage directly states that most of the U.S. population should increase their intake of ______.

A．protein

B．fats

C．starch and fiber

D．sandwiches

使用钢丝绳吊装物品，启动和制动的要求是（）。

A.启动和制动要缓慢

B.启动迅速，制动缓慢

C.启动和制动要迅速

D.启动缓慢，制动迅速

如果电动机外壳未接地，当电动机发生一相碰壳时，它的外壳就带有（）。

A.线电压

B.线电流

C.相电压

D.相电流