题目

My sister isthan me, but I am funnier than her. A . hard-working B . more hard-working C . much hard-working D . the most hard-working 答案：B 下列叙述正确的是：                                                                A．送血离心的血管都是动脉    B．动脉血含养料多，静脉血含废物多    C．动脉血在肺泡周围转变成静脉血    D．静脉血只在静脉中流淌