30. It is the sixth month ______ in which exports have fallen because of the economy crisis.
| A．in a row | B．in total | C．in all | D．in order |
Our house is the most _____ one in the street; it is painted red.
| A．permanent | B．indifferent | C．predominant | D．prominent |
It has been laid down that each student must _____ a composition to the teacher once a week.
| A．turn in | B．give up | C．put forward | D．bring out |
Radium salts, which have been found to _____ in bones, give rise to cancers of the bone.
| A．pile up | B．build up | C．keep up | D．pull up |
Having said he would mend the clock, he discovered that he had not brought the _____ tools for the job.
| A．concise | B．correct | C．right | D．precise |
The country needs a _____ government. We have had three Prime Ministers in a year.
| A．stationary | B．changeless | C．constant | D．stable |