With international ______ and education exchanges increasing every year, the number of Chinese students studying abroad has increased rapidly.

Peter isn’t______ at all; he always pays the bill when we eat in a restaurant.

 It’s bad ___________ for a man to smoke in the public places where smoking is not allowed.

There is no _____ that taking regular physical exercise is good for your heart.

Gerneally speaking, it is difficult to breathe at a high       of Tibet (西藏).