优生学具有生物学上的意义.Eugenics has a biological significance.对 “ 积极 ” 优生学和 “ 消极 ” 优生学往往加以区分.A distinction is often made between " positive " and " negative " eugenics.消极优生学的范例是试图破坏一种对人体有害的隐性基因.An example of negative eugenics woul...
Don't skateboard or roller skate on the road..不要在路上玩滑板或溜冰.There are children, there can also learn to roller - skate.有小孩的话, 去那里还可以学滑旱冰.Scooter, Finger Scooter, Finger Skateboard, Roller Skate, Snow Board. Toy and Ga...
木虱会侵害活体植物并啃咬它们的茎。Woodlice attack living plants and gnaw at the stems.但一种叫作马铃薯木虱的昆虫负有部分责任.Part of the answer is an insect called the potato psyllid.该细菌似乎和马铃薯木虱的亲缘生物 —— 柑桔木虱——传播的细菌有亲缘关系.It appears to be to a bacterium tran...