题目

Teenagers at one German school are learning how to achieve happiness alongside subjects like maths and languages. The class sit in a circle with their eyes shut and count from one to ten: one begins, the next voice comes from the far right, a third from the other side. The aim is to listen for an opportunity to shout the number without clashing(冲突) with another voice or leaving a pause. On the first try, most of the young Germans try to be first, while a few are too shy to join in. But by the fifth round, they develop a rhythm. The message: giving other people space but also confid13．用一种试剂鉴别1-己烯、碘化钾溶液、苯、四氯化碳四种液体，应选用（　　）A．盐酸B．FeCl3溶液C．水D．溴水