There are more than 200________ stars in our galaxy A. billions B. billions of C. billion
_______ I work with my classmates after school.
There are many supermarkets in this town, but we think this is _______ of all.
We are very _______ that many students use the Internet every day.
--Did you buy anything on your vacation?--Yes, I bought _______ for my parents.
--_______ does your father watch TV? --He is always busy, so he _______watches TV.