We are now in the age of great changes. Everything sometimes ________ before it is felt.

A．change

B．had changed

C．has changed

D．changed

习 * * 在回答中国梦的实质时指出：“中国梦归根到底是人民的梦，必须紧紧依靠人民来实现，必须不断为人民造福。”