__________ there are a large number of chemical factories，the air is likely to be polluted.
| A．That | B．Where | C．Once | D．As |
27. He is above ______ in his lessons. That's the results of his hard work.
| A．average | B．all | C．anyone | D．Everyone |
28. Do you happen to know the proverb, “Shoot two ____ with one arrow”?
| A．birds | B．hawks | C．dogs | D．Wolves |
29. On March 12, the students were planting trees ____ the classroom.
| A．in the back of | B．at the back of | C．to the back of | D．on the back of |
30. Once Jerry is back of you, there will be nothing halfway. The underlined part probably means _____.
| A．hate | B．support | C．beat | D．Face |
31. Don't throw out the _____ with the bath water.(prov.)
| A．boy | B．girl | C．baby | D．Child |