如图示，固定长直导线通以图示方向的电流，导线旁有一导线框，两者共面，框中通以顺时针方向的电流时，框的运动是（   ）

选词填空。

    Hello! I'm Linda. I have a good e-friend. Her name is Zhang Yun. Her English name is Betty. She is a Chinese girl, but she lives in the UK with her parents. Her father is a doctor and her mother is a teacher. She is ten years old. She call me big sister. She is good at English. She likes Chinese and I also like Chinese. She likes singing and playing basketball. This is my good e-friend. Do you want to know more?

某些西方资产阶级史学家称鸦片战争为“通商战争”，认为这场战争是英国为维护正常贸易而进行的，这种观点
①是错误的，掩盖了战争的侵略性质    ②是正确的，认识到战争的实质
③是为英国殖民者进行辩护            ④混淆了现象和本质的关系

沙  ____       A.将土块放入盛水的烧杯中，看是否有气泡冒出

空气____       B.将干燥的土块放在石棉网上烧，当土块冒烟时，是否闻到臭味

腐殖质____     C.用玻璃棒把放入水中的土块搅拌均匀，沉淀后看颗粒分布