Answer:

1. They sold cars.

2. The teacher punished the boy.

3. The little girl laughed at the beggar.

4. The knew it.

5. He didn't tell the lie.

6. The mansons built the house.

Xin hay nhất!

$@Rí$ gửi ạ! 

$1.$ They sell cars.

=> They sold cars. 

-> Quá khứ của sell là sold (irregular verb)

$2.$ The teacher punishes the boy.

=> The teacher punished the boy.

-> Punish-Punished (regular verb)

$3.$ The little girl laughs at the beggar.

=> The little girl laughed at the beggar.

-> Laugh-laughed (regular verb)

$4 .$They know it

=> They knew it.

-> Know-knew (irregular verb)

$5.$ He does not tell the lie.

=> He does not told the lie.

-> Tell-told (irregular verb)

$6.$ The mansons build the house.

=> The mansons built the house. 

-> Build-Built (irregular verb)

$Julri$