【判断题】Vaccines do not contain the type of germ that makes you sick.
【简答题】What changes do vaccines acctually make to people?
【判断题】在 HTML5 语法中,标记的属性的属性值可以不放在引号中。
【多选题】关于html 5中属性是否可以省略属性值,说法正确的有?
C.
当在元素中使用了boolean属性且省略属性值,相当于该boolean属性的属性值为true
D.
当在元素中使用了boolean属性且省略属性值,相当于将该boolean属性的值设为空值("")
E.
当在元素中没有使用boolean属性,相当于该boolean属性的属性值为false
【单选题】How do vaccines protect humans from diseases according to paragraph 2?
A.
By training the immune system to fight weaker versions of the disease.
B.
By passing information on how to fight the disease to the immune system.
C.
By weakening the disease so that the immune system can defeat it.
D.
Introducing the disease to the body, so that survivors have already fought it.
【判断题】vaccines do not guarantee complete protection from a disease.
【判断题】Some vaccines do not contain any germs.
【判断题】在HTML5语法中,标记的属性的属性值可以不放在引号中。
【单选题】在 HTML 中, ( ) 属 性 可以设置链接地址