英语难题The one written in pencil?

sth written in chalk 你能看出来吧被动writtensth written in pencil/written with a pencil如果用with chalk 比如I want to write with chalk, 要是with chalk , 你可以看出不是被动句吧!如果 sth written 就用in chalk, chalk 是不可数所以不加a.没有说不能用in chalk例句The one written in pencil/in chalkI want to write with a pencilI want to write with chalk 不可数