Now, multiple sclerosis is a type IV hypersensitivity reaction, or cell-mediated hypersensitivity.

多发是IV型超敏反应，即细胞介导超敏反应。

Combustion is an extremely common reaction type.

燃烧是一种极为见的反应类型。

The final reaction type is dehydrogenation, and it, somewhat obviously, is the removal of hydrogen atoms from alkanes.

最后的反应类型是脱氢， 从某种程度上，是从烷烃中去除氢原子。

Allergic rhinitis is a type 1 hypersensitivity reaction, which is a type of allergic reaction that starts with exposure to an environmental allergen.

过敏鼻炎属I型超敏反应，即由环境过敏原暴露所引起的过敏反应。