一个工艺中实际方差为150实际标准偏差为20在这工艺中提取25个样值则标准估算误差为()
A.0.2
B.0.8
C.4.0
D.5.0
E.7.5
参考答案:C
Lingling is a ________ girl and she does everything ________. [ ]
A. careless, careless
B. carelessly, careless
C. careful, carefully
D. carefully, careful
下图是高等植物的光合作用和细胞呼吸过程简图,请据图回答问题
参与光反应的色素有胡萝卜素、叶黄素、叶绿素a、()等。