=> Can I wear jeans at the wedding party-Of course not. You'll have to dress up

Dress up= Put on smart clothes (ăn mặc sáng sủa, đẹp đẽ) 

=> A committee has been set to examine the question

Set up= establish( sáng lập, thành lập)

=> Our class football team lost the match, so we tried to cheer them up

Cheer up= encourage (cỗ vũ)

*Toàn bộ từ được sử dụng đều là phrasal verb.

1. You'll have to dress up at the wedding party.

 - dress up (phrasal verb): ăn mặc trang trọng, lịch sự.

2. A committee has been set up to examine the question.

 - set up (phrasal verb): dựng lên, thành lập = establish (verb)

3. Our class football team lost the match, so we tried to cheer them up.

 - cheer up (phrasal verb): phấn chấn lên (ý nghĩa an ủi, khuyên vui vẻ lên)