It is early in the morning, about seven o'clock. Peter is on the bus. He's going to school. There are many people on the bus and it is a bit hot. Peter is sitting by a window with a book in his hands. The bus driver is driving slowly(慢地). Most people on the bus are using their mobile phones. A girl in a red sweater is standing near Peter. She looks very happy. She is reading some funny things on her mobile phone. A fat boy behind him is busy playing games on  his mobile phone. A tall man is Jack. He is listening to music on the mobile phone. He’s about thirty years old. They are all busy and happy.

一元二次方程$3x^2-x=0$的解是（   ）

数千年中华文化提供的生活方式、民俗民风、中华料理、养生医药、建筑样式、传统节日、民族民间艺术、体育、礼仪，尤其是文字书法……是我们民族的瑰宝，即使在西风强劲的环境下，人们也日益认识到了自己传统文化的可贵。这启示我们要（    ）

①传承民族文化，增强文化自信和自觉

②奏响主旋律，增强我国的文化软实力

③提高辨别能力，区分先进与落后文化

④继承优秀传统文化，维护文化多样性

如图是测定光合作用速率的装置，在密封的试管内放一新鲜叶片和二氧化碳缓冲液（作用是使装置内的CO₂浓度保持相对稳定），试管内气体体积的变化可根据毛细玻璃刻度管内红色液滴移动距离经计算获得。在不同强度的光照条件下，测得气体体积变化如图所示。