“世界上最遥远的距离是，我们俩一起出门，你去买‘苹果’五代，我去买五袋苹果。”要解决这一搞笑微博所折射的贫富差距问题，最根本的是要（  ）

原产地在非洲的经济作物是（）

阅读理解

    Mrs Gill lived next door to Nita．Every afternoon，Mrs Gill took a walk．She said it kept her young．Nita liked to talk with Mrs Gill when Mrs Gill came back．Mrs Gill was always happy after her walk．She often showed Nita something she had found．like a beautiful red leaf．

    One afternoon, Mrs Gill looked sad．Nita asked her why．

    I am sad about all the trash (垃圾)on the street．"she said．"I never saw so much trash in this neighbourhood(街区)!What happened?"

    "Mrs Trent moved．"said Nita．"She often went out each morning and picked up trash before．I often saw her on my way to school．"

    Mrs Gill looked very▲．"I thought I knew everything about this neighbourhood!"she said．"But you see more than I do!"

    "Well．1 wish I could do Mrs Trent's job．But you know,my back(背)often hurts．It's really hard for me to pick things up，"she said．

    "I could do that．"said Nita．

    Mrs Gill said．"I will carry the trash bag!You can use my gloves so your hands can stay clean．"

    Nita put on the gloves．She picked up pieces of paper．She picked up boxes．And Mrs Gill carried the bag．Lots of people stopped to thank Mrs Gill and Nita．The street looked much better．

    "Thanks, Nita．"said Mrs Gill．"Let's call ourselves the clean-up team!"

根据材料内容选择最佳答案。

图1是关于“一氧化碳的化学性质”的问题探究式课堂教学中解决问题阶段，甲同学设计了证明CO具有还原性的实验装置．