At first, there are flat, red, itchy spots called macules.
一开始出现平整、发红、有痒感的斑疹。
Flat spot
原声例句
Osmosis-微生物
飘（原版）
Mrs. Calvert did not like barbecue food and declared that the smells remained in the house for days, so her guests always sweltered on a flat unshaded spot a quarter of a mile from the house.
卡尔弗特太太不喜欢野宴上的食品，并且声称好几天之后房子里都还有那些气味，所以她的客人就常常被安排在一个离住宅四分之一英里的平坦而没有遮荫的地点热汗淋漓地吃着。
英语百科
Flat spot
A Flat spot, or Wheel flat, is a fault in railroad wheel shape. A flat spot occurs when a rail vehicle's wheelset is dragged along the rail after the wheel/axle has stopped rotating. Flat spots are usually caused by use of the emergency brake, or slip and slide conditions that causes wheels to lock up while the train is still moving. Flat spots are more common in the autumn and winter when the rails are slippery. Flat spots can also be caused by faulty brakes or wheelset bearings.