Videos, recordings and other learning aids are usually used __________ textbooks in language learning.
Not until all the fish died in the water _____ how serious the pollution was.
.– George and Lucy got married last week. Did you go to their wedding?– No, I _____. Did they have a big wedding?
We all know the truth _____ there are air, water and sunlight there are living things.
My interests include football, bowling and surfing the web_____ studying my favorite subjects.
--- I saw the Smiths at West Beijing Station this afternoon.--- You __________. They are still on holiday in Hawaii.