simultaneous a.同时的，同时存在的
simutaneous a.同时进行的
spontaneous a.自发的；本能的'
例句：
How do we know that the signature is contemporaneous with the document?
The extraneous "k" has never been explained.
从来没有人解释这个不相干的“K”是什么意思。
Simple websites don’t have extraneous information.
简洁的网站没有冗余的信息。
To you, it looks like merely extraneous whitespace.
对于您来说，它仅仅是无关紧要的空格。
Death was almost instantaneous.
当时生命垂危。
His hospitality was instantaneous and all-embracing.
他的款待及时而周到。