I don’t know .
A what to do it B how to do it C how to do D what should I do
—It smells terrible. What has happened here?
—Look, there is much waste gas _____ from the chemical factory.
| A．pour | B．pouring | C．poured | D．pours |
—Have you finished your homework?
—Not _____. There are still some exercises to be done.
| A．already | B．yet | C．just | D．ever |
_____ the environment is important for human beings.
| A．Take care of | B．Taking care of |
| C．Took care of | D．Take the care of |
This is the most beautiful park I have _____ visited.
| A．ever | B．yet | C．never | D．already |
Xi’an is a city with many places of interest and __ tourists come here every year.
| A．thousand of | B．thousand | C．thousands | D．thousands of |