光学显微镜下观察正常的紫色洋葱鳞片叶外表皮细胞装片时，视野中看不见的结构是（　　）

    I have a twin sister, Jenny. She has ____（长的）hair than me. Many people think ____（我们）must have a lot of things in ____（普通的，常见的）. That's not true. Jenny is creative. She won the best ____（奖项）in the school talent show. She likes making friends, so she is more ____（外向的）. But I like staying at home. And I watch TV ____（两次）a week because I have to go to school every day. I always get better ____（分数）but she is much less hard—working. So maybe I should help her. ____（然而）, we also have some similarities. We ____（都）like sports and going shopping, so we can talk about and ____（分享）everything. I love my sister.

国家质检总局近日抽检了9家电商平台在售的275批次产品，“TOSHIBA东芝”、“荣事达”、“TCL” 等品牌的19批次电磁炉被检出不合格，存在安全隐患。作为青少年应该（  ）