根据句意和首字母提示，以适当形式填写正确的单词。

1. Is it possible to carry on a c___________ with all this noise on the street?

2. He was lying in the sun looking very r___________ and happy.

3. This year World Health Day examines the health of mothers and children in d_______countries.

4. The manager of the company asked him to have a complete p___________ examination.

5. Our country's e___________ great changes in the last 30 years.