单项选择题
A. could not have been solved B. could not be solved C. must not be solved D. should not have been solved
There has been a decrease（）the number of students enter...
单项选择题There has been a decrease（）the number of students entering the Medical College this year.
A.on B.over C.in D.of
March is the third month of（）A.a yearB.yearC.yearsD.the...
单项选择题March is the third month of（）
A.a year B.year C.years D.the year
One of the serious problems facing us is（）of how to get...
单项选择题One of the serious problems facing us is（）of how to get enough manpower,
A. that B. it C. which D. what
