He ended his speech with a remark_______ knowledge _______power.

A．which; was

B．that; is

C．which ; is

D．that ; was

关于医学模式的本质，下列描述最正确的是()

A.医学实践的总结

B.对疾病的总结

C.医学理论研究的发展

D.临床医学实践的发展

E.卫生管理、卫生发展战略研究的发展