Although ____ many times, she still made the same mistake.
If you take____risk of not wearig a seat belt, you are at___risk.
Before traveling in space, you must know what it might feel like_____in an imaginary environment.
She's really _____ yoga these days - she does three classes a week.
Since you can solve the problem,I don’t feel_____worthwhile taking such trouble.
The scientists are studying the effects of human activities______the environment.