已知：a是两位数，b是一位数，如果把b放在a的左边，那么所形成的三位数是﹙ ﹚
100b+a．
The tree _____________ are green in spring.[ ]
A. leafs
B. leaves
C. leaf
根据句意及首字母补全单词。
1 .I have a r_____ model. It can fly high.
2. I h_____ to walk all the day.
3. The crops in the f_____ grow well.
4. I have a c_____ of stamps.
5. The teacher gave him a p_____ for his study.
