1. If the pollution increases , more and more people will
→Câu điều kiện loại 1
2. It is necessary to have a day to celebrate our parent
→It's necessary to V : cần thiết để làm gì
3. Keeping people from littering the garbage is very difficult
→It is very difficult to keep people from littering the garbage
CHÚC BẠN HỌC TỐT!
Cho mk xin ctlhn nha! Thanks nhìu!