1. healthily -> healthy ( Walking is a good way to keep fit and stay healthy )

2. than -> to ( The woman prefers looking after her children to cooking dinner. )

3. thousand -> thousands (I think you will find that book in the library because there are thousands of different books there. )

4. leaved -> left ( He left the office and disappeared two days later )

5. angry -> angrily ( They looked angrily at me when I broke the mobile phone last night )

1. Walking is a good way to keep fit and stay healthily.

- healthily -> healthy ( stay healthy: giữ gìn sức khỏe )

2. The woman prefers looking after her children than cooking dinner.

- than -> to ( prefer + N/Ving + to + N/Ving: thích cái gì hơn cái gì )

3. thousand -> thousands ( do có tobe "are" )

4. He leaved the office and disappeared two days later.

- leaved -> left ( quá khứ đơn của "leave" là "left" )

5. They looked angry at me when I broke the mobile phone last night.

- angry -> angily ( "look" trông câu này là động từ thường nên sau nó là trạng từ )