When ______ comes to research into heart disease and its effects on the body, we do not have adequate substitutes for the use of animals.

What do you think of Jay Chou’s song ?—I think it’s ________best song in the world. Isn’t it _______ beautiful one?

What do you think of earthquake, Zhang Hong?— Terrible. people lost their hometown during the earthquake.

We can’t see the sun _____.[ ]

Lily doesn′t write as_________ as Lucy.