$\text{1.}$
$\text{Question 33.What did you do last night?}$
$\text{Question 34.They have learnt English for four years.}$
$\text{Question 35.We should make blankets for children who are very ill.}$
$\text{Question 36.The lakes are full of rubbish, so we should ask our friends to clean them this Sunday.}$
$\text{2.}$
$\text{Question 37.He’s had a bad cold because he didn’t wear enough warm clothes. (because+clause:bởi vì)}$
$\text{Question 38.Although she likes walking, she never goes to school on foot. (although+clause:mặc dù)}$
$\text{Question 39.Why don’t you donate books to children? (Why don't we/you + Verb (nguyên mẫu)...?)}$
$\text{Question 40.I have taken part in doing voluntary work since 2015.}$
$\text{(S+began/started+V_ing...=S+have/has+P.P+since/for+...)}$