Cho đúng dạng từ trong ngoặc

1.      George (fall) _____________ off the ladder when he was painting the ceiling.

2.      Since Peter (leave) _____________ school, I (not hear) ______________ from him.

3.      How long (you/ learn) _______________ how to write?

4.      Up to the present, we (write) _______________ almost every lesson in the book.

I think he’ll leave as soon as he (know) _______________ the news.