Chinese vessels ________ 646,000 square kilometers in the southern Indian Ocean in search of the missing Malaysian flight MH370.

Scientists say they have found a way to produce the human body’s own cancer-killing cells through gene treatment, ____ new hope to cancer sufferers.

Tom and Mike are good friends. They often         each other from being punished by the          teacher. 

After he retired from office, Tom ___ painting for a while , but soon lost interest. 

A great deal of advanced science and technology has been _______ since China carried out the reform and opening policy.