Only if a teacher has given permission is a student allowed to leave the room.

学生只有得到老师的许可才能离开教室。

《牛津词典》

He would not be allowed to leave the country.

他不准离开这个国家。

《柯林斯英汉双解大词典》

He has been allowed to leave the country and is on his way to Hawaii.

他已获准离开该国，现正在前往夏威夷的途中。

《柯林斯英汉双解大词典》

He says unless he receives a direct order from President Susilo Bambang Yudhoyono, the Sri Lankans will not be allowed to leave the vessel.

VOA: standard.2009.10.27

The secretary said the woman had not been allowed to leave her home after her marriage, until her husband was injured and could no longer earn a living.

VOA: standard.2010.04.28

It allowed me to leave the island and build myself separate from the long-long shadow of my twin.

VOA: special.2009.02.14

In addition they are allowed to leave their laptops and toiletries in their bags.

BBC: Boarding pass barcodes 'can be read by smartphones'

He said the police officers took his details and he was eventually allowed to leave.

BBC: Row over photo in shopping centre

They were not allowed to leave the lab, nor were they allowed to nap.

CNN: Sleep deprivation spurs hunger