①从现在做起,从小事做起
②说老实话,办老实事,做老实人
③在大是大非面前要诚实守信,小事情则不必
④勇于承认过错,主动承担责任
A:①②③
B:①③④
C:②③④
D:①②④
It's 11: 00 pm now, but the light in Peter's room is still on. He must have forgotten _______ before going to bed.
绿藻A是某种单细胞绿藻,能够合成物质W.某小组为探究氮营养缺乏对绿藻A增殖及物质W累计的影响,将等量的绿藻A分别接种在氮营养缺乏(实验组)和氮营养正常(对照组)的两瓶培养液中,并在适宜温度和一定光强下培养.定时取样并检测细胞浓度和物质W的含量,结果如图.