下列属于我国公民基本义务的是（   ）
①维护祖国的安全、荣誉和利益  ②弘扬艰苦创业精神 ③关爱他人生命 ④维护国家统一和全国各民族团结 ⑤维护他人人格尊严

下列疾病中，都属于传染病的是（   ）

这封家书是在什么情况下写的？写信的目的是什么？

Tom is from London. He's now in Beijing with his parents. His father and mother teach in a school. He studies in a middle school. The school is four miles from his home. He usually walks to school. He says, "It can make me healthy." Sometimes when it rains, he takes a bus. He's never late, and he's always the first one to get to school. He's good at all his subjects, and often helps us with our English. We all love him very much.