take sth. with a grain of salt 这个习语的字面意思是“和一撮盐一起吃下去”，为什么要与盐一起吃呢？
据说这个习语要追溯到罗马时代，罗马将军庞培曾发现一种解毒剂，必须和着一小把盐才服得下去。解毒剂难咽，加了盐也许好咽些，于是这句习语用于描述对一些不靠谱的，值得怀疑的东西，得“和着盐”才能勉强接受。
现在，对某件事情或某人说的话有所保留，将信将疑，持怀疑态度，就可以说 take it with a grain of salt.
英文注释是：To take something with a grain of salt means to accept it but to maintain a degree of skepticism about its truth.
例句：
1）Uncle Bill tells some stories, but we take what he says with a grain of salt because he sometimes likes to exaggerate or makes
things up.
比尔大叔讲了好些事情，不过对他所说的要有所保留，有时他喜欢把事情夸大。
2）This is only a sort of handout. You may take it with a grain of salt.
这只是一份分发的资料，你大可以不必相信。
3）Horoscope is fun, but it’s not necessarily accurate. I always take it with a grain of salt.
星座这东西很有趣，但是并不一定准确。我对它一向将信将疑。