Đáp án:

`1.`They have sent around 8,378 satellites to space since the launch of Sputnik 1 in 1957.

`->` Around 8,378 satellites have been sent to space since the launch of Sputnik 1 in 1957.

`\text{Cấu trúc bị động ở Hiện Tại Hoàn Thành :}`

`\text{S + have/has + been + V(pp) + .... }`

`2.` Do you know the reason? Many people around the world learn English for this reason.

`->` Do you know why many people around the world learn English for this reason.

`3.`Most parents want their children to study a useful subject leading to a good job.

`->` Most parents would rather their children to study a useful subject leading to a good job.

1.They have sent around 8,378 satellites to space since the launch of Sputnik 1 in 1957.

=>Around 8,378 satellites have been sent to space since the launch of Sputnik 1 in 1957.

2. Do you know the reason? Many people around the world learn English for this reason.

=>Do you know why many people around the world learn English?

3.Most parents want their children to study a useful subject leading to a good job.

=>Most parents would rather their children studied a useful subject leading to a good job.