Do you know how much this costs?其中为什么cost要加s?不是疑问句都要用原型吗?

Do you know how much this costs?其中为什么cost要加s?不是疑问句都要用原型吗? --- Do you know how much that dictionary costs? a smile costs nothing,but gives so much 为什么cost要加s?先不看give加s this coat cost him100 yuan.cost为什么不是costs?感激不尽 what's thing make you so happy?how do you know this?为什么一个要DO stickers,much,cost,how,do,the,you? do you know something bad happened .do you know不是疑问句吗为什么some 翻译:1.How do you sell the paper?2.How much does this pen cost -how much do I owe you for lunch?-__.It's nothing.为什么不是you a How much do you___C_____ for this computer?A.cost B.take C.s (A How much) (B money)do you (C cost) (D for) this bike? How do you like this book?为什么用 Very much