Question

useful work they are doing！ A。What B。what a C。How a D。how

His parents teachers.
Aboth are B.are all
c.all are D.are both

Answer 1

选择A
what 引导名词性感叹句 后面的work是名词，所以用what
但是work这个名词不可数，不能加冠词a

His parents 他的父母，是两个人，首先确定用both，不能用all，all表示三个人及以上
那么就both are 和are both中选择，选择are both

The blue and red jackets are both beautiful.
蓝色夹克和红色夹克都很漂亮。

Such lessons are both difficult and expensive to teach.
这样的课教起来既困难重重又价格不菲。

希望能采纳，谢谢了

Answer 2

正确答案 A D
what修饰名词work 而work是不可数名字 所以前面不加冠词 a 所以选A

Answer 3

B 。。。 感叹句
A 他们的父母都是老师 两个人用both

Answer 4

B
D

祝你学习愉快！ (*^__^*)
请及时采纳，多谢！

Answer 5

B。what a

D.are both