Tom __(drop)the vase and___(break)it a moment ago

Tom __(drop)the vase and___(break)it a moment ago Donˊt drop the vase. Don't drop the vase.哪里错了 一道英语小grammar!If you drop the vase,it will break.为什么不是If you drop the vase,it breaks.这不是一定会发生的东西吗? Tom bought the coat yesterday.同义句转换tom __ __ the coat __ __ __ If you drop the vase,it Your will break.花瓶掉了不是一定会碎吗?为什么说will I THINK I __(DROP) IT DURING THE CONCERT.中为什么填DROPPED不是WILL DROP be adj to/ for表示对于某人 两个都对吗?the vase is precious __ him Tom __ the river and __ the boy.填空 ( )《not》 break the vase. 英语翻译汤姆正在给那只老虎拍照Tom __ __ __ __ __ the tiger Tom and Jack share the kitchen改为同义句Tom and Jack share the kitchenThis kitchen__ __ __ __ __. It was in the room __ his son broke the vase.A.where B.in which C.whicn D.that It was the room __ his son broke the vase.A.in which B.that C.where D.which Tom's hat ahd mine are the same的同义句Tom's hat __ __ __ __mine who knocked the vase __ (off还是over)?如题~例句是：I knocked the vase off the shelf and broke it.但答案给的是over到底哪个对呢? Tom is the __（good run) in our class Tom asks me __(read)books in the library.