有关五星级饭店送餐服务的要求正确的是()。
A.应24小时提供送餐服务
B.送餐菜式品种不少于8种
C.有可挂置门外的送菜牌
D.送餐车应有保温设备
参考答案:A, B, C, D
---Peter , where did you guys go for the summer vacation?
----We________ busy with our work for months, so we went to the beach to relax ourselves.
A.were
B.have been
C.had been
D.will be
已知函数f(x)=x2-(1+2a)x+aln x(a为常数).
(1)当a=-1时,求曲线y=f(x)在x=1处切线的方程;
(2)当a>0时,讨论函数y=f(x)在区间(0,1)上的单调性,并写出相应的单调区间.