- Peter, where is your brother?- He________his English homework. (1.0)
A. is doing
B. does
C. will do
D. did
I________my friend Tim for 5 years. (1.0)
A. know
B. have known
C. knew
D. will know
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