---What are you busy with ?--- We are carrying out a research ____ the causes of cancer.
When you go abroad,you’ll find the food at home is___ better than __ outside.
He knows China very well. That is,he has__ good understanding of___ Chinese history.
I always take something to read when I go to the doctor’s I have to wait.
I have had my bike , and I’m going to have John my radio tomorrow.
The little boy is dirty from head to foot because he in the mud all morning.