kipa：the cloth skullcap or yarmulke traditionally worn by male Jews。

　　kipa 也写成 kippah，意思是犹太小圆帽。看图片貌似我们经常看到的伊斯兰餐厅里回族同胞戴的应该也是这种。

　　helmet：a protective headgear made of hard material to resist blows

　　helmet 就是头盔，顺便说下大家注意拼写，这个词总被小猪我顺嘴读成哈姆雷特。头盔大家都见过就不多说了，顺便说下，图上的这只名字叫做Stig，是英国BBC最受欢迎真人秀《Top Gear》的明星。

　　tin foil hat：A piece of headgear made from one or more sheets of tin foil, aluminium foil, or other similar material, the hats worn in the belief that they act to shield the brain from such influences as electromagnetic fields, or against mind control and/or mind reading

　　tin foil hat 就是锡纸帽，这种帽子戴来纯粹是给自己找心理安慰的……