A:②④
B:②③
C:①③
D:①④
在柴油机的压缩冲程中,气体的温度和内能变化情况是( )
阅读短文,判断正误。
Hello,I'm Peter. I'm from Canada. I'm 11 years old. I'm 1. 6 metres and 40 kilograms. I like reading books. Every morning, I go to school with my good friend Ben. We go to school on foot. Ben is 10 years old. He's 2 kilograms heavier than me. But I'm 2 cm taller than him. We study in Red Wood School. Lucy is my sister. She's 1 year older than me. She likes drawing pictures. She is taller and stronger than me.
计算:(3﹣π)0﹣3tan60°+(﹣13)﹣1+|4|