1. If we reuse plastic bags and bottle, we will help the environment.
2. If people use recycled products, they will save money.
3. The boy will be ill if he eats so many green fruits.
4. If the soil is polluted, the plants will die.
Cấu trúc: If + S + V(s, es) + O, S + will/can + V(nguyên thể) + O