Negative variation
[醫] 負性變異, 陰性變易
?? 詞語組成解析
negative
['n?ɡ?t?v]
adj. 消極的，否認的;[數]負的;[心]反抗性的;無預期結果的;
n. 否定詞語;否定的觀點;消極性;[攝]底片;
vt. 否定;拒絕;
negat否認+ive形容詞后綴 → 否認的；n. 底片
??? 情景例句
But personally I believe a business letter should end with Very truly yours, not Sincerely.
還行，喬治。但是我個人相信一封商業信函應該以“敬上”結尾，而不是“謹啟”。
If Grade A is not available, Grade B will do.
如果一等品無貨，二等品也可以。
Oh, look! said Ann. What's that? She pointed at one of the things.
“看啊！”安說，“那是什么？”她指著一件展品問。