题目：
用所给词的适当形式填空 。
1. Tom has _______(12) color pens.
2. Tom's birthday is August ________(12).
3. Is March the _______(3) month of a year?
4. There are ________(90) students in her class.
5. The new skirt are ________(100) yuan.
答案：
1. twelve 2. twelfth 3. third 4. ninety 5 one hundred
