目的观察睾丸干细胞因予(SCF)在燃煤型氟中毒大鼠睾丸组织中的表达变化.方法将20只雄性SD大鼠随机分为对照组,低氟组,中氟组,高氟组(后三组为染毒组),各5只.除对照组外,余各组均喂饲含不同比例的燃煤型氟中毒病区煤烘玉米的饲料,制作燃煤型氟中毒动物模型.90d后,取大鼠睾九,采用透射电镜观察睾丸支持细胞的超...
Which of the following shows that elephants are different from human beingsA.They stay around the dead body for a long time.B.Only females stay together for a long time.C.The mothers teach their daughters and set a good example.D.The older animals would