练习材料：
Lesson 18-2 Porpoises
Porpoises and sharks are natural enemies. It is possible that upon such an occasion a battle ensued, with the sharks being driven away or killed.
Whether it be bird, fish or beast, the porpoise is intrigued with anything that is alive. They are constantly after the turtles, who peacefully submit to all sorts of indignities. One young calf especially enjoyed raising a turtle to the surface with his snout and then shoving him across the tank like an aquaplane. Almost any day a young porpoise may be seen trying to turn a 300-pound sea turtle over by sticking his snout under the edge of his shell and pushing up for dear life.
ˈpɔːpəsɪz ænd ʃɑːks ɑː ˈnæʧrəl ˈɛnɪmiz. ɪt ɪz ˈpɒsəbl ðæt əˈpɒn sʌʧ ən əˈkeɪʒən ə ˈbætl ɪnˈsjuːd, wɪð ðə ʃɑːks ˈbiːɪŋ ˈdrɪvn əˈweɪ ɔː kɪld.
ˈwɛðər ɪt biː bɜːd, fɪʃ ɔː biːst, ðə ˈpɔːpəs ɪz ɪnˈtriːgd wɪð ˈɛnɪθɪŋ ðæt ɪz əˈlaɪv. ðeɪ ɑː ˈkɒnstəntli ˈɑːftə ðə ˈtɜːtlz, huː ˈpiːsfʊli səbˈmɪt tuː ɔːl sɔːts ɒv ɪnˈdɪgnɪtiz. wʌn jʌŋ kɑːf ɪsˈpɛʃəli ɪnˈʤɔɪd ˈreɪzɪŋ ə ˈtɜːtl tuː ðə ˈsɜːfɪs wɪð hɪz snaʊt ænd ðɛn ˈʃʌvɪŋ hɪm əˈkrɒs ðə tæŋk laɪk ən ˈækwəpleɪn. ˈɔːlməʊst ˈɛni deɪ ə jʌŋ ˈpɔːpəs meɪ biː siːn ˈtraɪɪŋ tuː tɜːn eɪ 300-paʊnd siː ˈtɜːtl ˈəʊvə baɪ ˈstɪkɪŋ hɪz snaʊt ˈʌndə ði ɛʤ ɒv hɪz ʃɛl ænd ˈpʊʃɪŋ ʌp fɔː dɪə laɪf.
海豚和鲨鱼是天然仇敌，双方可能随之发生搏斗，搏斗结果是海豚赶走或咬死鲨鱼。
海豚对凡是活的东西都感兴趣，不管是鸟、是鱼，还是野兽。它们经常追逐海龟，海龟则温顺地忍受着各种侮辱。一只小海豚特别喜欢用鼻子把海龟推到水面，然后像滑水板一样把海龟从水池的这一边推到那一边。几乎每天都可以看到一只小海豚把鼻子顶入一只300磅重的海龟的硬壳下面，拼命地把它翻过来。
任务配置：L0、L3、L4
知识笔记：
单词与短语
It is possible that upon such an occasion可能随之发生...
drive away 赶走
pushing up for dear life拼命地把它翻过来
练习感悟：学着用单词造句
