A：加固黄河大堤
B：在上游修筑水库
C：搞好中游的水土保持工作
D：多挖几条入海河道
扩写下列句子
①书上有一只灰雀。
②花儿散发出香味。
③马路上有汽车
Our teachers do whatever they can for us. They think that's their duty.
