Only by increasing the number of doctors by 50 percent _______ properly in this hospital.

_________ you take an active part in physical activity ______ be able to keep fit and stay healthy.

He said that not until the heavy snowblocked the express _________ how serious the weather was.

The beautiful sunset ourattention，and westopped to watch it

Mark_______have hurried. After driving at top speed .he arrived half an hour early.