$\text{1.}$ It's very exciting to fly in the countryside.

$\text{→}$ It's + adj + to-V

$\text{2.}$ I started doing voluntary work 3 years ago.

$\text{→}$ started/ began + V-ing = have/ has + Ved/ P2

$\text{3.}$ We don't have to change the dates of our trip.

$\text{→}$ not necessary = don't have to: ko cần phải

$\text{4.}$ Would you like me to show you how to use it?

$\text{→}$ want = would like: muốn

$\text{5.}$ I spent 2 hours walking to her village.

$\text{→}$ take (sb) + time to-V = spend + time + V-ing

$\text{6.}$ The Museum of Ethnology is visited by millions of tourists every year.

$\text{→}$ Câu bị động thì HTD: S + is/ are/ am + Ved/ P2 + (by)

$\text{7.}$ Jane's sister doesn't make craft as well as her.

$\text{→}$ sau V là adv

$\text{→}$ well là adv của good

$\text{8.}$ Amy suggested going to her uncle's farm at the weekend.

$\text{→}$ suggested + V-ing

=>
1. It's very exciting to fly a kite in the countryside.
2. I started doing voluntary work three years ago.
3. We don't have to change the dates of our trip.
4. Would you mind if I showed you how to use this?
5. I spent two hours walking to her village.
6. The Museum of Ethnology is visited by millions of tourists every year.
7. Jane's sister doesn't make crafts as well as she does.
8. Amy suggested going to my uncle's farm at the weekend.