$\text{21.}$ A $\text{→}$ surprised

$\text{→}$ adj -ed chỉ người

$\text{→}$ adj -ing chỉ vật

$\text{22.}$ whom $\text{→}$ which 

$\text{→}$ whom chỉ người

$\text{→}$ which/ that chỉ vật

$\text{→}$ nếu bỏ câu which đi thì nghĩa ko thay đôi $\text{→}$ which 

$\text{23.}$ reading $\text{→}$ to read

$\text{→}$ advise sb to-V: khuyên ai làm gì

$\text{24.}$ punishing $\text{→}$ punished

$\text{→}$ bị phạt $\text{→}$ V-ed

$\text{25.}$ A $\text{→}$ In spite of/ Despite

$\text{→}$ Although + S + V

$\text{→}$ In spite of/ Despite + N/ V-ing

VIII.

$\text{41.}$ I don't know as much as her about it.

$\text{→}$ not as ... as: so sánh ko ngang =

$\text{42.}$ It is difficult for my French friend to use chopsticks.

$\text{→}$ It is + adj (for sb) to-V

$\text{43.}$ The owner of the house is thought to be abroad.

$\text{→}$ S + be thought to-V

$\text{44.}$ The sea was too rough for the student to go swimming.

$\text{→}$ too + adj (for sb) to-V

$\text{45.}$ I had my house painted last week.

$\text{→}$ S + have/ get + N + Ved/ P2.