生化变种
参考答案：
指原核生物一个种内的菌株，按生理生化性状的差异来划分的组群，不考虑致病性等其他特征的异同。
To keep safe is very important. When you are alone at home, you should ______ to protect yourself.
①have a list of phone numbers to call for help, such as 110,119 and 120
②play computer games while boiling some water
③keep the door locked
④pay attention to the gas, water and electricity
⑤let anybody in immediately when you hear the doorbell [ ]
A. ①④⑤
B. ②③⑤
C. ①③④
滥用抗菌药物最大的危害是
A．破坏人体内微生态环境的稳定B．细菌对抗菌药物产生广泛而迅速的耐药性C．引起菌群失调D．引起二重感染E．造成内源性感染
