--Yes, he has been an engineer for thirty years.

A. Who B. How

C. What D. Which

A. have B. has C. are D. is

【题目】— How often are the Olympic Games held?— __________ four years.
A.Every
B.Each
C.In
D.For

A. enough； to B. so ；that C. very；that D. too；to

【题目】Jane studies in ___________ at No.1 Middle School.
A.Class seven
B.Seven Class
C.Class Seven
D.seven class

【题目】When we got to the city center, __________ shops were still open, but most of them were closed.
A.the
B.some
C.many
D./

A. science;scientist B. science;science

C. scientist; science D. scientist; scientist

-- B , thanks. I prefer a glass of water.

A. Both B. Neither C. Either

— A doctor.

A. do; grew B. do; growing

C. be; is going to grow D. be; grows