DearSir,

We are sorry to hear that you have been （） problems with your new product. 　　While we do ask that our （） contact their dealer in the event of a problem, we recognize that, in your case, it his would be impossible. Therefore, if you will carefully （） the unit in its original carton and send it to us, our “doctors” will put it through a thorough examination to determine the source of the problem. 　　Again, I am sorry that you experienced this （） and wish to thank you for your （） and for purchasing our product.

正确答案：experiencing；

customers；

package；

difficulty；

patience