a small pile of earth that a mole leaves on the surface of the ground when it digs underground 鼹丘（由鼹鼠挖洞扒出的泥土堆成）
If you say that someone is making a mountain out of a molehill, you are critical of them for making an unimportant fact or difficulty seem like a serious one. [V and Ns inflect] [disapproval]
The British press, making a mountain out of a molehill, precipitated an unnecessary economic crisis.
英国报界小题大做，酿成了一场不必要的经济危机。