组别
培养基中的添加物
MRSA 菌
1
100μg/mL蛋白质H
生长正常
2
20μg/mL青霉素
3
2μg/mL青霉素+100μg/mL蛋白质H
死亡
A：细菌死亡与否是通过光学显微镜观察其细胞核的有无来确定
B：第2组和第3组对比表明，使用低浓度的青霉素即可杀死MRSA菌
C：实验还需设计有2μg/mL青霉素做处理的对照组
D：据实验可知蛋白质H有很强的杀菌作用，是一种新型抗生素
下面措施中，哪一种对保持生态环境最有利?
American school life is different from (和……不同) Chinese. American students usually get to school at around 8:30 in the morning. They put their school bags in their lockers (柜子) and only take one book, one notebook and one pen to each class. In class, American students can sit in their seats (座位) when (当……时候) they answer their teachers questions At around 12:00 students have lunch. American students don’t go home for lunch. They have it at school. Most students like pizza(比萨), hot dogs or hamburgers. At 1:00 in the afternoon, they start to have classes. Their classes are usually over(结束) at three o’clock. Then they join in the activities （活动）of clubs or sports.
