象煞有介事煞有介事xiàng shā yǒu jiè shì

act as if in real concern(/in all seriousness/in a matter of-fact manner);make a show of being in earnest;pretend to be serious
❍ ～，一次一次倒来问了好几次。开给他们一张失单了，隔两天又要开，……(《茅盾文集》Ⅷ—283)They act so important.First they come and make me fill out a Stolen Property List.Then two days later they come again and make me fill out another.
❍ 这班先生们.～地提倡“一次革命论”，……(《毛泽东选集》645)Thus,these gentlemen who,in all apparent seriousness,are pushing the“theory of a single revolution”.

象煞有介事xiàng shà yǒu jiè shì

象煞：极相像。介事：那样的事。即好像真有那么回事。多形容装模作样，似乎真有了不起的一套。