-Chúc bạn học tốt-
`56.` The doctor gave him a warning not to smoke because it's dangerous. (warned)
`⇒`The doctor warned that smoking is very dangerous
`57.` In her eyes, all her classmates are not trustworthy. (thinks)
`⇒`She thinks all of her friends are unreliable
`58.` She was grateful to them for their hospitality. (thanked)
`⇒`She thanked them for their hospitality.
`59.` He didn't want to participate in the volunteers' activities. (take)
`⇒`He does not want to take participate in volunteer activities.
`60.` They didn't let him get in the disco because he was under 18. (prevented)
`⇒`They prevented him from entering the disco because he was below.