以下属于生活于水体中层的鱼类有()
A. 白鲢
B. 草鱼
C. 鲤鱼
D. 泥鳅
用红光(R)和远红光(FR)交替照射处理莴苣种子,观察对种子萌发率的影响,结果见下表。从以下实验数据可以得出:()
A. 红光促进莴苣种子萌发
B. 莴苣种子萌发需红光和远红光交替照射
C. 远红光促进莴苣种子的萌发
D. 红光的促进作用可以被随后照射的远红光降低
Intheeventofasmallbunkeroilspillondeckoccurringwhilebunkering,youshould().
A. washdowntheareaimmediatelywithafirehose
B. washdowntheareawithkerosene
C. covertheareawithabsorbentmaterial
D. covertheareawithfoam
Smalloilspillsondeckcanbepreventedfromcontaminatinganywatersby().
A. pluggingallscuppersanddrains
B. placingfloatingboomsaroundtheship
C. regularlyemptyingalldrippans
D. thoroughlydrainingallbunkeringhoses