I have no doubt that if the students' interest in the subject is aroused, they will ______ the challenge and commit more of their time and energy to their studies.

A．face up to

B．keep pace with

C．stand out against

D．fall back on

近来年，我国食品、药品领域出现了多起恶性事件，如“苏丹红”、“瘦肉精”等。这些事件的存在说明了                                     [ ]

①国家应加大执法力度，依法打击侵犯消费者合法权益的违法行为  

②应加强企业的法制教育  

③消费者应提高 * * 意识，依法维护自己的合法权益  

④我国现阶段，法律体系还不够健全  

A、①②③④      

B、①③④      

C、②③④      

D、①②③