设函数y=e^x+1，则y''=（）
Thistest________anumberofmultiplechoicequestions.
SinceWilliamhadbeenseriouslyillforseveralmonths,hisparentswereworriedabout________toreturntoschoolfull-time.
二维随机变量(X,Y)在D=（x，y）0<y<1-x2上服从均匀分布，求Z1,Z2联合分布。
“Haveyoumovedintothenewflat?”“Notyet.Therooms________(paint).”
，其中n为正整数,则f'(0)=()