It is not right ____ in public places.
| A．smokes | B．smoking |
| C．smoked | D．to smoke |
Look! A large group of birds are flying __________the mountain!
| A．past | B．through |
| C．over | D．across |
It’s important for us to keep food __________in the fridge, especially in summer.
| A．fresh | B．delicious |
| C．terrible | D．tasty |
-We have 7 people here , but the car only has 5 seats.
-I think we need to solve this __________now.
| A．matter | B．trouble |
| C．problem | D．question |
Her son began to play __________piano when he was only three. Now he’s very good at it .
| A．an | B．a | C．the | D．/ |
—I'm sorry to keep you waiting for me so long.
—.
| A．I don't think so | B．That's right |
| C．It doesn't matter | D．I'd love to |