This type of loan is(frequent)_____ used for this purpose.

Vitamin B enables the body to _____ full use of the foo...

单项选择题Vitamin B enables the body to _____ full use of the food taken in.

These construction workers are required to participate ...

单项选择题These construction workers are required to participate _____ the safety training program.

It is hard(guess)_____what comments the manager will ma...

填空题It is hard(guess)_____what comments the manager will make on the design.