Four and _______ half hours of discussion took us up to midnight, and _______ break for cheese, chocolate and tea with sugar．
A．a；aB．the；the
C．不填；theD．a；不填
Only by increasing the number of doctors by 50 percent _______ properly in this hospital．
A．can be the patients treated
B．can the patients be treated
C．the patients can be treated
D．treated can be the patients
A serious study of physics is impossible _______ some knowledge of mathematics．
A．againstB．before
C．beyondD．without
It was only after he had read the papers _______ Mr．Gross realized the task before him was extremely difficult to complete．
A．whenB．thatC．whichD．what
It may not be a great suggestion．But before _______ is put forward, we’ll make do with it．
A．a good oneB．a better one
C．the best oneD．a best one
The watch was very good, and he _______ 20 percent down for it．
A．paidB．costC．boughtD．spent
