The cat jumped through the window.
→ The boy saw the cat jump through the window
They allowed him to write a letter to his wife
→ They let him write a letter to his wife
She wants to play the piano.
→ She enjoys playing the piano
After she had done homework she went to school.
→ Before she went to school, she had done homework
______________________________
$1$. to be invited
$2$. practising
$3$. to see
$4$. being robbed
____________________________
$19$. B
$20$. A
$21$. D
$22$. B