练习材料：
Lesson 7-1 Bats
Not all soundsmade by animals serve as language, and we have only to turn to that extraordinarydiscovery of echo-location in bats to see a case in which the voice plays astrictly utilitarian role.
To get a fullappreciation of what this means we must turn first to some recent humaninventions. Everyone knows that if he shouts in the vicinity of a wall or amountainside, an echo will come back. The further off this solid obstruction,the longer time will elapse for the return of the echo. A sound made by tappingon the hull of a ship will be reflected from the sea bottom, and by measuringthe time interval between the taps and the receipt of the echoes, the depth ofthe sea at that point can be calculated. So was born the echo-soundingapparatus, now in general use in ships.
bæts
nɒt ɔːl saʊndz meɪdbaɪ ˈænɪməlz sɜːv æz ˈlæŋgwɪʤ, ænd wiː hæv ˈəʊnli tuː tɜːn tuː ðæt ɪksˈtrɔːdnridɪsˈkʌvəri ɒv ˈɛkəʊ-ləʊˈkeɪʃən ɪn bæts tuː siː ə keɪs ɪn wɪʧ ðə vɔɪs pleɪz əˈstrɪktli ˌjuːtɪlɪˈteərɪən rəʊl.
tuː gɛt ə fʊl əˌpriːʃɪˈeɪʃ(ə)nɒv wɒt ðɪs miːnz wiː mʌst tɜːn fɜːst tuː sʌm ˈriːsnt ˈhjuːmən ɪnˈvɛnʃənz. ˈɛvrɪwʌnnəʊz ðæt ɪf hiː ʃaʊts ɪn ðə vɪˈsɪnɪti ɒv ə wɔːl ɔːr ə ˈmaʊntɪnsaɪd, ən ˈɛkəʊ wɪlkʌm bæk. ðə ˈfɜːðər ɒf ðɪs ˈsɒlɪd əbˈstrʌkʃən, ðə ˈlɒŋgə taɪm wɪl ɪˈlæps fɔː ðərɪˈtɜːn ɒv ði ˈɛkəʊ. ə saʊnd meɪd baɪ ˈtæpɪŋ ɒn ðə hʌl ɒv ə ʃɪp wɪl biː rɪˈflɛktɪdfrɒm ðə siː ˈbɒtəm, ænd baɪ ˈmɛʒərɪŋ ðə taɪm ˈɪntəvəl bɪˈtwiːn ðə tæps ænd ðə rɪˈsiːtɒv ði ˈɛkəʊz, ðə dɛpθ ɒv ðə siː æt ðæt pɔɪnt kæn biː ˈkælkjʊleɪtɪd. səʊ wɒz bɔːnði ˈɛkəʊ-ˈsaʊndɪŋ ˌæpəˈreɪtəs, naʊ ɪn ˈʤɛnərəl juːz ɪn ʃɪps.
任务配置：L0+L4
知识笔记：
单词：1、bat：蝙蝠，2、extraordinary：非凡，特殊，3、echo-location：回声定位，4、utilitarian：功利的，功利主义，5、appreciation：欣赏，感谢，6、mountainside：山腰，7、obstruction：梗阻，阻碍，8、elapse：过去，推移，流逝，9、tap：轻敲，敲击，10、hull：船体，船壳，11、interval：间隔，间隙，12、receipt：收据，收条，回执，13、apparatus：仪器，设备，14、
音标：
感悟：这篇文章，我记得第一次读的时候，感觉跟读都很难跟得上，今天来读，已经能比较熟练地读出来了，这个进步还是看得见的。
