$\text{*Cấu trúc sử dụng câu 1 và 3}$
$\text{Clause 1 because clause 2}$
$\text{= Clause 2 so clause 1}$
$\text{Cấu trúc sử dụng trong câu 2}$
$\text{Câu bị động thì HTĐ -> S + am/is/are + Vpp}$
$\text{1. Nam can answer that question because he is very intelligent}$
$\text{= Nam is very intelligent so he can answer that question.}$
$\text{2. They plan to invite their close friends for dinner tonight}$
$\text{= Their close friends are planned to invited tonight.}$
$\text{3. Mai gets bad marks because she doesn't do her homework.}$
$\text{= Mai doesn't do her homework so she get bad marks}$