问题
选择题
关于青霉素生产的叙述，正确的是[ ]
A．青霉素是青霉菌生长代谢中重要的初级代谢产物
B．用紫外线、激光、化学诱变剂处理青霉菌再经筛选的方法可以选育高产菌种
C．发酵罐接种后必须进行灭菌处理
D．在青霉菌生长的稳定期，活菌数不再增加，青霉素产量也不再增加
答案
答案：B
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关于青霉素生产的叙述，正确的是[ ]
A．青霉素是青霉菌生长代谢中重要的初级代谢产物
B．用紫外线、激光、化学诱变剂处理青霉菌再经筛选的方法可以选育高产菌种
C．发酵罐接种后必须进行灭菌处理
D．在青霉菌生长的稳定期，活菌数不再增加，青霉素产量也不再增加
答案：B
Mary loved small animals．One morning while she was walking in the forest，she found weak birds in the grass．She took them home and put them in a small cage．She cared them with love and the birds both grew ．They thanked her a wonderful song every morning． But something happened one day．Mary left the door of the cage open．The larger bird flew from the cage．She thought that it would ．As it flew close，she grasped(紧抓)it．She was very excited to catch it．Suddenly she felt strange．She opened her hand and looked sadly at the bird．Her great love had killed the bird! The other bird was moving back and forth(来回)in the cage．Mary could its great need for freedom(自由)．It wanted to fly into the clear and blue sky．At once，Mary took the bird the cage and let it fly away．The bird circled once，twice，three times… Mary enjoyed watching the bird flying and singing ．Suddenly the bird flew and landed softly on her head．It sang the sweetest song that she had ever heard． The easiest way to lose love is to hold it too tight．The best way to keep love is to it wings．
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