Today is Friday. Peter has six classes today. He goes to school at 7:30 a.m. At 8:00 a.m., he begins his first class. The first class is English. At 9:00 a.m., he has math. Peter likes math because it’s interesting. At 10:00 a.m. she has a biology class. Peter thinks it's very boring. Then at 11:00 a.m., he has a history class. That's his favorite subject. He can learn a lot about the past from history.
    Peter has lunch at school at about 12:00. Then he has a short break. At 1:30 p.m., he has a music class. At 2:30 p.m., he has a P.E. class. Peter likes this afternoon, because music and P.E. are easy and interesting. School is over at 4:00 p.m. Peter is happy because he can go home and have a good time on Saturday and Sunday.
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校戏剧社正在排练课本剧。小明只顾表现自己，总是抢别人的戏份，导致排练很不顺利。社长小刚觉得小明虽然热情很高，但应该学会与大家合作。假如你是小刚，会怎样委婉的劝说小明？请把劝说的话写下来。

定义：点P是△ABC内部或边上的点（顶点除外），在△PAB，△PBC，△PCA中，若至少有一个三角形与△ABC相似，则称点P是△ABC的自相似点.

例如：如图1，点P在△ABC的内部，∠PBC=∠A，∠PCB=∠ABC，则△BCP∽△ABC，故点P是△ABC的自相似点.

请你运用所学知识，结合上述材料，解决下列问题：

在平面直角坐标系中，点M是曲线y= $\frac{3\sqrt{3}}{x}$ （x＞0）上的任意一点，点N是x轴正半轴上的任意一点.

地球上的氧气主要来自绿色植物的（    ）

下列关于 ①乙烯  ②苯 ③乙醇 ④乙酸 ⑤葡萄糖等有机物的叙述不正确的是（　　）