| 1 | B:I'm sorry. It' s out of stock. | |
| 2 | The book is in/out of stock. | |
| 3 | The reason is that the product you need has been out of stock. | |
| 4 | By virtue of its super quality ,this product is often sold out in many areas. | |
| 5 | By virtue of this superior quality, this product is often sold out of stock in many areas. |