6. At first, the speaker was referring to the problem of pollution in the country, but halfway in her speech, she suddenly _____ to another subject.
A. committed
B. switched
C. favored
D. transmitted
7. At no time _____ other countries.
A. China will invade
B. will invade China
C. will China invade
D. invade will China
8. Be here on Friday _____ the latest.
A. at
B. by
C. for
D. in
9. Because the whole country is in a financial dilemma, the government calls on us to _____ economy.
A. make
B. practice
C. carry
D. develop
10. Before he started the work, I asked the builder to give me an _____ of the cost of repairing the roof.
A. assessment
B. estimate
C. announcement
D. evaluation
