根据点的极坐标和直角坐标的互化,解决下列问题
在光合作用过程中,选项中各产物出现的先后顺序正确的是( )
①氧化性叶绿素a ②CO2 ③H2O ④ATP ⑤O2 ⑥NADPH.
下列物质中,不属于人体内环境组成成分的是
Our teacher was very happy because _____failed the examination.