The strange arrows with flat heads are a notation used in the literature of gene expression and gene regulation , and they mean " inhibits " 这些奇怪的平顶箭头是在文学上用来表示基因表达和基因控制的记号法，他们表示"抑制" 。
Countersunk flat head screws common head style with type h or type z cross recess - product grade a . steel of property class 8 . 8 , stainless steel and non - ferrous metals H型或z型十字槽沉头螺钉. a级产品. 8 . 8级,不锈钢和非铁类金属钢特性
The electrical outlet of korea is two aperture , and it is round hole electrical outlet , because this does not carry the electric equipment of 3 bolt , bicephalous flat bolt buys changeover outlet to korea hind ( flat head is changed into round head ) can use 韩国的插座都是两孔的，而且是圆孔插座，因此不要带三头插销的电器，两头扁插销到韩国后买转换插头（扁头转换成圆头）就可以使用。
