G-菌细胞壁具有的毒性成分是
A．肽聚糖B．脂多糖C．磷壁酸D．脂蛋白E．脂质双层
参考答案：B
解析：G-菌细胞壁外膜中的脂多糖是毒性成分。
I shall never forget the years____ I lived in the countryside with the farmers, ____ has a great effect on
my life.[ ]
A. that, which
B. when, which
C. which, that
D. when, who
设备的操平找正指的是什么？
