1/用Being缩短句子 Being…是be的现在分词形式(Be+ing构成)。
Be…包括(is、am、are、was、were、been)。
所以，Being…可以缩短由(is、am 、are、was、were、been)构成的从句，使其变成"现在分词短语"、缩短句子。
★可缩短"一般现在时态"从句
A/ He is so ill, he can not go back to work yet.
Being so ill, he can't go back to work yet.
他病的很严重，现在不能回去工作。
★可缩短"一般过去时态"从句
B/ He was so ill He could not go back to work。
Being so ill, he could not go back to work。
他已经病的很严重，他不能回去工作。
C/ As it was a bank holiday, all the offices were shut.
Being a bank holiday, all the offices were shut.
今天是银行假日，所有办公点都关门。
D/They were so busy that they couldn't do another thing at the same time.
Being so busy, they couldn't do another thing at the same time.
如此繁忙，他们不能同时间内做另一件事情。
★缩短"现在进行时态"从句 When I am using this dictionary, I find it is very useful.
Using this dictionary, I find it is very useful.
2/用Having done缩短句子 Having done…是"现在分词的完成形式"、表示主动。
描述从句的动作早于主句动作。 可用其缩短"主动语态的"：
"现在完成时从句、
过去完成时"从句：
★We have invited her here to speak, so we had better go to her lecture.
Having invited her here to speak, we had better go to her lecture.
(Having invited…动作早过go的动作、用现在分词完成形式)
★He (has/had) been ill for a long time, he (needs/needed) time to recover before he can/could go back to work. Having been ill for a long time, he (needs/needed) time to recover before he can/could go back to work.
他病了很长时间，所以他在回去工作前需要时间康复。
3/用Having been done来缩短从句
"Having been done"~是"现在分词完成形式/被动语态"。
可以缩短：
1/ "现在完成时"/被动从句、
2/"过去完成时态"/被动从句：
★I have been made redundant，so I am going abroad.
Having been made redundant, I'm going abroad.
我现在被定为超编人员了，所以我打算出国。
★She had been invited to the party, so she hurried to the party。
Having been invited to the party, she hurried to the party.
她被邀请去参加宴会，所以她急匆匆的向宴会赶去。
总结：
1/ "having done"…可以缩短"主动语态"的：
"现在完成时态"从句(have done)、
"过去完成时态"从句(had done)。
2/ "having been done"…可以缩短：
"现在完成时态"被动从句(have been done)、
"过去完成时态"被动从句(had been done)。