我国统一的商品代码层次结构共分为四层，依次是（） ["门类、大类、中类、小类","大类、中类、小类、品类","门类、大类、中类、品类","大类、小类、品类、品种"]
标准溶液装入滴定管之前，要用该溶液润洗滴定管2～3次，而锥形瓶也需用该溶液润洗或烘干。
In the west of the （）lie the Colorado Plateaus and the Columbia Plateaus. ["Rocky Mountain","Coast Range","Cascades Mountai"]
Wise buying is a positive way in which you can make your money go further. The （）you go about purchasing an article or a service can actually （）you money or can add （）the cost.
Take the （）example of a hairdryer. If you are buying a hairdryer, you might （）that you are making the （）buy if you choose one （）look you like and which is also the cheapest （）price. But when you get it home you may find that it （）twice as long as a more expensive （）to dry your hair. The cost of the electricity plus the cost of your time could well （）your hairdryer the most expensive one of all.
So what principles should you （）when you go out shopping?
If you （）your home, your car or any valuable （）in excellent condition, you’ll be saving money in the long （）
Before you buy a new （）,talk to someone who owns one. If you can, use it or borrow it to check it suits your particular （）
Before you buy an expensive （）,or a service, do check the price and （）is on offer. If possible, choose （）three items or three estimates.
请在第（）处填上正确答案。 ["run","interval","period","time"]
The Constitutional Monarchy started at the end of the （）century. ["17th","16th","15th"]
证券投资的目的有哪些？
