答案：Ⅰ. 1 ― 5 BDDAA  6 ―10 CABDA  11 ― 15 CCADB  16 ― 20 DBACD  21 ― 25 BDBAC  Ⅱ. 1 ― 5 DBCBA  6 ― 10 CABCA  11 ― 15 CDDAD  16 ― 20 BAAAD   21 ― 25 CBDAB  Ⅲ. 1―5 DACCD  6 ―10 ACDBC 11 ― 15 CFEGD  Ⅳ . 1 . darkness / dark 2 . journey 3 . forced 4 . simple 5 . forehead 6 . wonder 7 . length 8 . satisfied 9 . smelly 10 . zones  Ⅴ . 1 . expected→expecting 2 . 去掉 reached 后面的 to 3 . usually→usual 4. same→the same 5 . 去掉 in 6 . 去掉 for 7 . √  8 . 在 much 前加 how 9 . spend→spending  10 . anyone→everyone

Ⅵ . One possible version:

Dear Mr Zhang ,

We know that this is the last lesson that you will give us . Soon we'll graduate and say good-bye to our school . At this moment , we don't know how to express ourselves . All we can say is "Thanks" .

Three years ago when we came to this school , we knew nothing about English . However , with your unselfish help , we have greatly improved our English in listening , speaking , reading and writing . We owe all this to you , because in the past three years , you have been working hard , trying your best to help us . We will remember all those lively and interesting lessons you've given us , which we will never forget .

Now let us all say again , "Thank you ,  Mr Zhang" .