用合适的介词或副词填空1.I called him yesterday,but he was______work.2.I

1.I called him yesterday,but he was 【at】 work. at work:在工作中； 2.I often take my dog【out】to the park【 for】a walk. take sth out:把.带出去；for a walk:散步； 3.I have many books【about】animals.These books help me learn a lot 【on/about】how to keep animals. about/on：关于,有关； 4.That mountian looks【like】an elephant's trunk. look like=be like:【和.相似】 5.I'm afraid【of】big dogs. be afaid of:害怕