题目

以下关于力学现象的分析中不正确的是（ ）A.飞机的机翼上凸下平，是利用流体压强与流速的关系来获得升力的B.轮船通过船闸从下游开到上游，船闸是利用连通器原理工作的C.拦河大坝上窄下宽是由于液体压强随深度的增加而减小D.堵住茶壶盖的小孔，水不容易被倒出是由于大气压强的作用 答案：【答案】C【解析】A．飞机的机翼上凸下平，气流通过上方时，速度大、压强小，气流通过下方时，速度小、压强大，在上下的压强差下获得升力，故A正确，不符合题意；B．连通器的底部连通，上面开口，船闸利用的是连通器原理使船能够在上下游来回航行，故B正确，不符合题意；C．由于同种液体中【小题1】He tried his best to find a way to s          the problem.【小题2】Ten players will take part in the final to c          for the gold medal.【小题3】Thanks to the soldiers, the villagers s          the flood.【小题4】The family began to d          the Christmas tree with glass balls and lights a week ago.【小题5】Tony was a          into the chess club last year.【小题6】As a r          (结果), I totally changed my shape.【小题7】There is no            (疑惑) that our life will become better and better in the future.【小题8】He set a            (目标) for himself of exercising at least three times a week.【小题9】There are different            (类型) of blood, as you know.【小题10】In many fields of our life, plastics has been used to            (取代) wood and iron.