第21小题为什么不能用in呢?They are making the cheerful stars __21___ co

第21小题为什么不能用in呢?They are making the cheerful stars __21___ colored paper.
第21小题为什么不能用in呢?
Months later, Junior 3 students will take the senior high school entrance exam. They are studying hard for this big __16__. Do they have time to do something to celebrate their middle school years? Many do.
Leng Jingze, 14, from Tianjin said that in her class students have already __17__ goodbye messages or letters for each other. They are also swapping (交换) photos.
“Even the head teacher has a project,” said Leng. “She __18___ to put all our class photos onto a CD and give each student __19___.”
Wang Zeyu, 15, in Changchun, Jilin said his __20__ are making “lucky stars” as graduation gifts. They are making the cheerful stars __21___ colored paper.
“Before __22___ a ‘lucky star’, you write some words for the person on the paper,” said Wang. “He or she can read the words __23__ they unfold the star.”
In Xiao Xia's school, each Junior 3 student will get a yearbook (年刊), in which the graduating classes will put__24__ photos and self-introductions.
Xiao said, “We have written a poem in the ancient style as the self-introduction!”
“Our class may be not the one with the __25__ school grade but it must be the most creative one,” said Xiao. “I feel lucky to study in such a class!”
( ) 16. A. challengeB. mistakeC. school D. attraction
( ) 17. A. read B. writtenC. looked D. watched
( ) 18. A. pretends B. refuses C. allows D. plans
( ) 19. A. one B. all  C. it D. this
( ) 20. A. parentsB. students  C. teachers D. classmates
( ) 21. A. from B. of C. to D. in
( ) 22. A. writing B. reading C. makingD. bringing
( ) 23. A. becauseB. though  C. before D. when
( ) 24. A. theirB. ourC. his D. its
( ) 25. A. loudest B. lastC. worst  D. best
16-20 ABDAD 21-25 BCDAD

通常是被动语态中较常见
be made of sth ...用 xx 材料制作
make A of B 这种说法不常见,一般用 with 最多,可惜答案中没有这个选项.
make sth in ...后面除了产地外,也有可能说明形状、颜色、尺寸...,但是和材料无关.