—Do you know _______ at that time last night?
—Yes, a report for a newspaper.
A:what was Linda writing
B:what will Linda write
C:what Linda was writing
D:what Linda will write
关于摩擦起电与感应起电,下列说法正确的是( )
(Ⅰ)当a=0时,求曲线y=f(x)在点(﹣1,f(﹣1))处的切线方程;
(Ⅱ)设g(x)=x2﹣x﹣1,若对任意的t∈0,2,存在s∈0,2使得f(s)≥g(t)成立,求a的取值范围.
读不同地点昼长随季节变化统计曲线图,图中a、b、c、d四地,自转线速度由快到慢依次是( )