26. The secretary telephoned Mrs. Philip and found she had some available rooms.

                      A                        B       C              D

答案： D

解析： available rooms改为rooms available；available这个形容词放在所修饰的词的后面。

27. I called at his office yesterday afternoon, but was told that he had gone half

         A                                           B                C

an hour ago.

         D

答案：  Ｄ

解析：　ago改为before；这句话的意思是：我昨天下午往他办公室打电话，但是被告知他一个小时以前就已经走了。

28. Jim spent his vacation going to Mexico, flying to London， and then visited  China.

                           A               B              C       D

答案： D

解析： visited改为visiting，注意与前面两个分词短语关系，并列关系，时态保持一致。另外，Ａ项中省略了一个介词in，spent sth (in) doing sth…，固定搭配用法，in可带可不带.

 29. Despite the fact that the South Pole is as snow-covered as the North Pole,

      A              B                            C

 is colder than the North Pole.

     D

答案： D

解析： is colder 应改为 “it is colder”；主句缺少主语，形式主语it代指South Pole；注意：不能省略it。

30. High school students must complete course in history and sciences by the time

                              A              B                            C

they will graduate.

           D

答案：　D

解析：　will graduate 改为graduated，用完成时表示将来时的一种用法.