我知道动词现在分词可以在句子中表伴随，那么我怎么区分哪些时候是伴随，哪些时候又不是了呢？谢谢。越详细越好！！！
參考答案:动词现在分词可以在句子中表伴随，作句子的状语。动词现在分词此时为非谓语动词形式。除现在分词外，还有过去分词表示伴随，作状语。
As I didn't receive any letter from him, I gave him a call.
-> Not receiving any letter from him, I gave him a call.
由于没有收到他的信，我给他打了电话。
If more attention was given, the trees could have grown better.
-> Given more attention，the trees could have grown better.
假如多给些照顾，那些树会长得更好。
典型例题
1）_____ some officials, Napoleon inspected his army.
A. Followed B. Followed by C. Being followed D. Having been followed
答案B. Napoleon 与follow 之间有被动的含义。being followed除表达被动之外，还有动作正在进行之意。 followed by（被…跟随）。本题可改为： With some officials following, Napoleon inspected his army.
2）There was a terrible noise ___ the sudden burst of light.
A. followed B. following C. to be followed D. being followed
答案B. 由于声音在闪电后，因此为声跟随着光，声音为跟随的发出者，为主动。用现在分词。
3）_______, liquids can be changed into gases.
A. Heating B. To be heated C. Heated D. Heat
答案C. 本题要选一分词作为状语。现在分词表主动，正在进行的；过去分词表被动的，已经完成的。对于液体来说是加热的受动者，是被动的，因而选C。它相当于一个状语从句 When it is heated，…
注意： 选择现在分词还是过去分词，关键看主句的主语。如分词的动作是主句的主语发出，分词就选用现在分词，反之就用过去分词。
(Being ) used for a long time, the book looks old.
由于用了很长时间，这本书看上去很旧。
Using the book, I find it useful.
在使用的过程中， 我发现这本书很有用。
