It is not so difficult to learn English well. ________ you need is listening, speaking, reading and writing it every day.
_____ all my teachers, Mr. Moore is the one who impresses me most.
Hurry up! The train ______. You know it ______ at 8:30 am.
In recent days ,with the help of our teacher , I have made ___ great progress in _____mathematics.
Mrs. Green always helps her mother even though going to work _________most of her day.
We have to admit that the biggest___________ facing the ecosystem is limited resources and the worsening environment.