练习材料：
NCE--第四册
Lesson 20-2 Snake poison
In fact, it would be an assistance to all carnivores though it would be a two-edged weapon when they fought each other. But, of the vertebrates, unpredictable Nature selected only snakes (and one lizard). One wonders also why Nature, with some snakes, concocted poison of such extreme potency.
In the conversion of saliva into poison, one might suppose that a fixed process took place. It did not; some snakes manufacture a poison different in every respect from that of others, as different as arsenic is from strychnine, and having different effects. One poison acts on the nerves, the other on the blood.
The makers of the nerve poison include the mambas and the cobras and their venom is called neurotoxic.
[ɪn] [fækt], [ɪt] [wʊd] [biː] [ən] [əˈsɪstəns] [tuː] [ɔːl] [ˈkɑːnɪvɔːz] [ðəʊ] [ɪt] [wʊd] [biː] [ə] [ˈtuːˈɛʤd] [ˈwɛpən] [wɛn] [ðeɪ] [fɔːt] [iːʧ] [ˈʌðə]. [bʌt], [ɒv] [ðə] [ˈvɜːtɪbrɪts], [ˌʌnprɪˈdɪktəbl] [ˈneɪʧə] [sɪˈlɛktɪd] [ˈəʊnli] [sneɪks] ([ænd] [wʌn] [ˈlɪzəd]). [wʌn] [ˈwʌndəz] [ˈɔːlsəʊ] [waɪ] [ˈneɪʧə], [wɪð] [sʌm] [sneɪks], [kənˈkɒktɪd] [ˈpɔɪzn] [ɒv] [sʌʧ] [ɪksˈtriːm] [ˈpəʊtənsi].
[ɪn] [ðə] [kənˈvɜːʃən] [ɒv] [səˈlaɪvə] [ˈɪntuː] [ˈpɔɪzn], [wʌn] [maɪt] [səˈpəʊz] [ðæt] [ə] [fɪkst] [ˈprəʊsɛs] [tʊk] [pleɪs]. [ɪt] [dɪd] [nɒt]; [sʌm] [sneɪks] [ˌmænjʊˈfækʧər] [ə] [ˈpɔɪzn] [ˈdɪfrənt] [ɪn] [ˈɛvri] [rɪsˈpɛkt] [frɒm] [ðæt] [ɒv] [ˈʌðəz], [æz] [ˈdɪfrənt] [æz] [ˈɑːsnɪk] [ɪz] [frɒm] [ˈstrɪkniːn], [ænd] [ˈhævɪŋ] [ˈdɪfrənt] [ɪˈfɛkts]. [wʌn] [ˈpɔɪzn] [ækts] [ɒn] [ðə] [nɜːvz], [ði] [ˈʌðər] [ɒn] [ðə] [blʌd].
[ðə] [ˈmeɪkəz] [ɒv] [ðə] [nɜːv] [ˈpɔɪzn] [ɪnˈkluːd] [ðə] mambas [ænd] [ðə] [ˈkəʊbrəz] [ænd] [ðeə] [ˈvɛnəm] [ɪz] [kɔːld] neurotoxic.
任务配置：
L0+L4
知识笔记 ：
练习感悟：
今天是课文第二部分，生词不好读。注意respect作名词，有“方面”的意思。今天的单词要注意重音的位置，以及英美音区别明显的几个词。句子方面要注意省略的部分。
