结构中含有咪唑环,侧链含有胍基的药物().
A.奥美拉唑
B.盐酸赛庚啶
C.富马酸铜替芬
D.西咪替丁
E.法莫替丁
参考答案:D
设A(x1,y1).B(x2,y2)两点在抛物线y=2x2上,l是AB的垂直平分线.
1)当且仅当x1+x2取何值时,直线l经过抛物线的焦点F?证明你的结论;
2)当直线l的斜率为2时,求l在y轴上截距的取值范围.
________ at the cafeteria before, Tina didn’t want to eat there again.
A.Having eaten
B.To eat
C.Eat
D.Eating