题干

下列化学实验基本操作中正确的是(   )

A:加热灼烧海带时要在蒸发皿中进行

B:蒸馏时,水从冷凝管上部通入,从下部流出

C:向某溶液中加入AgNO3溶液,生成白色沉淀,该溶液一定含有Cl﹣

D:分液时,碘的四氯化碳溶液从分液漏斗下口放出,水层从上口倒出

上一题 下一题 0.0难度 选择题 更新时间:2020-03-08 12:39:16

答案(点此获取答案解析)

D

同类题5

任务型阅读

    At what age does a child became an adult?____Here are a few examples.

    First, in some North American Indian culture, a boy became a man around the age of 13. At that time, he would go into the woods alone, without food or water, for several days.____Girls became adult women as soon as they were old to have babies, also around the age of 12 or 13.

    In the Jewish religion, children spend years studying their history and religion. Then, at age of 13 for boys and 12 for girls, they go through an important religious ceremony.____

    In Japan today, young people become legal adult at age 20. Each year on January 15th, they celebrate “Coming-of-Age Day”, when the 20-year-olds in a town are invited to attend to special ceremony.____

    Finally, in the United States, the passage into adulthood takes several years. American teenagers look forward to their 16th birthday because in most states that is the age when can get a driver's license. The legal age of adulthood is 18, when Americans can vote, get married and work full-time. However, they must wait until age 21 to buy alcohol.____

A. Many people celebrate their 21st birthday by having a drink with friends in a bar.

B. It's hard to answer the question.

C. The answer depends on your culture or religion.

D. From that day, they are adults, and they become responsible for their own religious development.

E. When he returned safely, he became an adult man.

F. The teenagers are not allowed to drink alcohol.

G. They wear traditional clothes, listen to speeches and visit old friends.