The experiment has _____ the possibility of the existence of any life on that planet, but it does not mean there is no life on other planets. [ ]

It’s not easy for primary students ______ themselves freely in class.

Mywatch______.Ihavelookedforiteverywherebutstill_________it.[ ]

(2013·新课标Ⅱ，12)Only by increasing the number of doctors by 50 percent________properly in this hospital.

Which would you prefer, tea or coffee I prefercoffee ______ milk.