院内感染的分类有：______、______、______、______.
参考答案：交叉感染；自身感染；医院性感染；带入传染
Nowadays, many people walk to work ________ Copenhagen Conference calling for living a low-carbon lifestyle to deal with global warming.
A．in relation to
B．in response to
C．in addition to
D．in opposition to
井下电缆为了防止火灾，要采用不延燃电缆。（）
