目前，人们把利用微生物在有氧和无氧条件下的生命活动来制备微生物菌体或其代谢产物的过程称为发酵。
参考答案：对
— Steve is good at writing short stories.
— Yes, he is. But he writes than us, so he doesn’t get good marks in writing.
A．most carefully
B．more carefully
C．less carefully
D．least carefully
下列哪些可引起呼吸频率变慢()
A．吗啡
B．羟丁酸钠
C．CO蓄积晚期
D．脑干损伤
E．颅内高压
