________,a man who expresses himself effectively is sure to succeed more rapidly than a man whose command of language is poor.
A、other things being equal
B、to be equal to other things
C、other things to be equal
D、were other things equal
答案解析：答案为A 如果选择B 就是 虚拟语气倒装表达法,were other things equal =if other things were equal （如果其它情况保持平等 / 势均力敌对）但是,和主句语气发生矛盾,不符合题意； 答案A 答案为独立主格结构主状语
独立主格结构为：名词/代词+分词结构(也就是非谓语动词独立主格结构）
由于后面为形容词,那么 系动词be+形容词 的系动词需要变为现在分词,也就是需要在be动词后面加上ing 即 be+ing =being 这种形式,因此A 为正确答案..
Other things being equal （主语=other thing +分词=being equal)
Other things being equal ,a man who expresses himself effectively is sure to succeed more raidly than a man whose command of language is poor
名词/代词+分词结构(也就是非谓语动词独立主格结构）在句子中当条件状语的作用.
中文意思（1）在其它情况相等的情况下,一个能有效地表达自己意思的人一定会要比语言驾驭能力差的人更快地取的成功 /获得成功.
中文意思（2）在其他情况/方面势均力对的条件下,一个能有效表述自己意思的人一定会一个语言驾驭能力差的人更快速的获取成功.