. In crowded streets, for the safety of people, it is ______ to drive faster than 20mph.
When you are in trouble, you may _______ your teacher and classmates for help.
The number of the people who can afford to buy their own house ______ more than 60%,but a number of houses _______.
I didn’t get a pay rise, but that wasn’t the right reason _______I left.
He started to study ecology and decided to _______his whole life to the science.
Recently our government policymakers are very _______about the rapidly rising food costs.