国家鼓励企业制定严于( )标准的企业节能标准。
A.国际B.行业C.国家D.国家、行业
参考答案:D
Those who suffer from headache will find they get ________ from this medicine.[ ]
A. relief
B. safety
C. defense
D. shelter
(-2b-5)(2b-5)=______.