A smile costs_______, but gives much.
There are so many kinds of computers in the shop. I really don't know ______ to choose. A. what B. which C. where
- Excuse me. May I use your eraser, please? -- Sure. ______ A. Watch out! B. Well done! C. Go ahead.
_____has your brother studied in New York? —For two years. A. How old B. How often C. How long
Bob promises to join in the football match ______ he has to help his parents on the farm. A. if B. as C. unless
-- Did you find the small village yesterday? -- Yes, without any difficulty, for it has ______ changed over years. A. hardly B. greatly C. clearly