几个英语句子1.John took down art while at school.2.A letter has be

1.John took up art while at school
2.A letter has been written to him,inviting him to the party
3.The man kept silent in the room unless spoken to
1.took up是从事的意思
2．信件是物体．后面要用伴随状语,是别人邀请他
3．相当与
The man kept silent in the room unless he is spoken to
省略了He is．．．是别人和他说话．．．相反．．．没有宾语的时候要用被动语态

The man kept silent in the room unless been spoken to
take up 还不是很好 改成major in试试 不过这样就改了两个单词了