19．聽短文，根據(jù)聽到的內(nèi)容補全所缺單詞．
Jack called Linda at ten （16）past four yesterday afternoon．He wanted her to come to his house to （17）help him to do his homework．But Linda wasn't at home when Jack telephoned her．She went to the bookshop with her mother．Mary，Linda's sister，（18）answered the phone and left a message on Linda's desk．Linda and her mother came back home at about half past four．Linda called Jack （19）back after she got the message and said （20）sorry to him．
分析 略
解答 16．past 17．help 18．a(chǎn)nswered 19．back 20．sorry
點評 略
