come back 和 be back、get back的区别是什么？

come back
回来
I'm going away and I may never come back.
我要走了, 可能永远不再回来。
记起, 回忆起
Gradually, the fragments of her childhood came back to her.
渐渐地, 她回忆起了童年生活的一些片断。
强烈反驳
“But you're just as guilty!”Jane came back.
“可你同样有罪!”珍反驳道。
〈非正〉重复说
I didn't hear you. Could you come back?
我没听见你说的什么, 你能重复一遍吗?

be back
回来,放回

get back
回来, 回家
What time will you get back?
你什么时候回来?
回到…上来
Things will not get back to normal soon after the earthquake.
地震过后一切都不会马上恢复正常。
退后
Get back, don't block the traffic.
往后退, 不要阻塞交通。
找回, 取回
I haven't got back the book I lent him.
我还没有收回我借给他的那本书。
报复, 向…报仇
I'll get back at them somehow for this!
我一定想法为这件事报复他们!

所以，区别应该很明显看的出来了吧