Invention can be as it may suddenly begin just by noticing something usual.A. accidental

问题补充：

Invention can be as it may suddenly begin just by noticing something usual.

A. accidental

B. careless

C. necessary

D. imaginative

答案：

(答案→)A. accidental

B. careless

C. necessary

D. imaginative

解析：A 考察形容词辨析。Accidental偶然的，careless粗心的；necessary必要的；imaginative虚构的，富于想象的；根据suddenly可知A正确。句意：发明有时也是偶然的，因为它仅仅开始于注意到了某个平常的某个东西。故A正确。