I________my friend Tim for 5 years. (1.0)
A. know
B. have known
C. knew
D. will know
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If we have a ten-day holiday, weLondon with my parents.(1.0)
A. visit
B. were visiting
C. will visit
D. visited
DNA is very useful for us, it many years ago. (1.0)
A. discovers
B. discovered
C. is discovered
D. was discovered
- Do you know now?- Because we need to develop our life. (1.0)
A. why we have more new inventions
B. why we had more new inventions
C. why do we have more new inventions
D. why did we have more new inventions
Don’t touch that-it’s hot! (1.0)
A. 不要碰它,很凉!
B. 不要碰它,很烫!
C. 不要碰它,有毒!
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