在探究“植物对空气湿度的影响”时,在裸地测量三次后求平均值,这样做的目的是 。
减少误差
实验常常要重复多次,取平均值,减少误差,得到比较可靠的结果。
Jack and Mike were found cheating in the exam, and _____ by their teacher at the moment.
[ ]
A. were scolded
B. are being scolded
C. have been scolded
D. were being scolded
正常精液pH值为()。
A.4.0~5.0
B.5.0~6.2
C.6.2~7.2
D.7.2~7.8
E.7.8~8.0