My grandfather was badly ill, so we asked him _________ smoking.
A:to give up
B:give up
C:gave up
D:given up
选修4-5:不等式选讲
已知函数 f(x)=4−|ax−2|(a≠0) .
印第安人说哥伦布是个“恶魔”,欧洲人说哥伦布是一个“有功之臣”。你认为下列哪个观点能客观公正地评价哥伦布的远航活动( )