Unit 1易混淆词语辨析
1. disease和illness
disease作名词，只用作可数名词，指各种疾病的术语，常表示特定的具体的病名、病类。如：
The business of doctors is to prevent and cure diseases.医生的职责是预防和治疗疾病。
illness也可以表示“疾病”。illness 既可用作可数名词也可用作不可数名词，它是最普通的用语，泛指得了某种疾病后身体的不适状态。如：
Several children are away from school because of illness.几个孩子因病没来上学。
2. be made of，be made from，be made in，be made by和be made into
be made of意为“由……制成的”，表示可看出原材料是什么。如：
This chair is made of wood. 这把椅子是木质的。
be made from意为“某物由…制成”，表示制成的东西完看不出原材料，在成品中已无法辨认。如：
Paper is made from wood. 纸是木头造的。
