_______matters most in learning English is enough practice.
With more and more forests _____, many animals are facing the danger of dying out.
As we all know, China is a developing country, _____ attracting more and more foreigners.
The beautiful town, _____ we spent our summer vacation last year , lies at the foot of a mountain.
—It’s such a beautiful day. Why not have a picnic with us? —_____. But I have a lot of homework to do.
—Listen! There is a knock on the door. Who _____ it be?—It must be Jack. Just now I sent for him.