Make sure that the（） of the gas pipes are sealed properly.

单项选择题One of the attractive features of the course was the way the practical work had been（）with the theoretical aspects of the subject.

A. embraced
B. adjusted
C. alternated
D. integrated

单项选择题A comprehensive market system should be established to（）the flow of talent, funds and materials.

A. suffice
B. necessitate
C. facilitate
D. fabricate