1.What is the problem of learning at home?

A Students don’t have computers.

B Teachers have no teaching plans.

C No one likes to learn with the students.

D Students cannot keep learning alone.

解析：选D。细节理解题。根据文章第一段However, it can be difficult for parents. Parents must go to work. Parents cannot stay at home. Somebody must learn with the children.可知，父母不能待在家里，但必须有人和孩子们一起学习，也就是说学生不能独自学习，故选D。

2._______ can learn with the children at home.

A Grandparents

B Teachers

C Classmates

D Friends

解析：选A。细节理解题。根据文章第二段Grandparents and other family members help look after the children. They can learn with the children, too.可知，（外）祖父母或家庭成员可以帮忙照顾孩子，和他们一起学习，故选A。

3.Who should be more carful?

A Children.

B Old people.

C Young people.

D Students.

解析：选B。细节理解题。根据文章第三段People over 65 must be careful. COVID-19 is more dangerous for them. Older people end up in hospital more often. Families must remember this.可知，新冠疫情对于老年人更危险，老年人更常住院，他们应该更小心，故选B。

4.What will be good for grandparents’ health at home?

A Children live in a big family.

B Parents look after the children.

C Grandparents learn with the children.

D All family members wear masks.

解析：选D。细节理解题。根据文章最后一段最后一句All family members must wear masks. It is important to keep the grandparents safe.可知，所有家庭成员必须戴口罩，这对保护祖父母的安全很重要，故选D。