27. Now and then they would ______ our house and have a talk with us.
| A．call on | B．drop in at | C．drop in on | D．drop in |
-Are you sure you won't come for a drink with us?
-, if you insist.
| A． | Not at all | B． | It depends | C． | All right then | D． | I don't care |
It's an either-or situation - we can buy a new car this year or we can go on holiday but we can't do.
| A． | others | B． | either | C． | another | D． | both |
Four andhalf hours of discussion took us up to midnight,andbreak for cheese,chocolate and tea with sugar.
| A．a;a | B．the; the | C．不填；the | D．a;不填 |
Only by increasing the number of doctors by 50 percent properly in this hospital.
| A．can be the patients | B．can the patients be treated |
| C．the patients can be treated | D．treated can be the patients |
A serious study of physics is impossiblesome knowledge of mathematics.
| A．against | B．before | C．beyond | D．without |