右图是模拟呼吸运动的模式图，下列描述正确的是

城市里有“超声波洁牙”美容店，超声波之所以能洁牙，是因为（　　）

阅读下文，回答相关问题

                                                                                                                     冯妇
        东瓯^①之人谓火为虎，其称火与虎无别也。其国无陶冶^②，而覆屋以茅，故多火灾，国人咸苦之。海隅之贾人适晋，闻晋国有冯妇善搏虎，冯妇所在则其邑无虎，归以语东瓯君。东瓯君大喜，以马十驷、玉二双、文锦十匹，命贾人为使者，求冯妇于晋。冯妇至，东瓯君命驾，虚左，迎之于国门外，共载而入，馆于国中为上客。明日，市有火，国人奔告冯妇，冯妇攘臂从国人出，求虎弗得。火迫于宫肆，国人拥冯妇以趋火，灼而死。于是贾人以妄得罪，而冯妇死弗悟。
【注解】①东瓯（ōu）：瓯，浙江温州的别称。②陶冶：烧制陶器（和冶炼金属），引申指砖瓦。

要使电阻在单位时间内产生的热量减少一半，则应（　　）

Peter: Do you have a brother, John?

John: Yes, I do. His name is Mike.

Peter: Is he older than you?

John: No, he is younger than me. He is three years younger than me. He is 12 years old.

Peter: He is shorter than you, isn't he?

John: No, he is a little taller than me.

Peter: Are his eyes bigger than yours?

John: Yes, his eyes are bigger than mine.

Peter: Who loves sports more, you or your brother?

John: He does. He is good at playing football.