( ) 16. Personal computers were in use in China when Amy visited the country in twentieth century(世纪).
A. the, / B. the, the C. / , / D. /, the
( ) 17. The magic show has been on 20 minutes. It has been on 2.p.m..
A. for, since B. in, since C. for, for D. since, for
( ) 18. – Where is your mother?
- She together with her friends Shanghai.
A. has gone to B. ha
ve gone to C. has been to D. have been to