背上双肩背包 ? backpack shoulders on the back 出厂序号 ? Manufacturer's serial number 如果你做到了以下几点，那你一定会学好英语的 ? If you do the following points, you must be fluent in English ..
双语例句
1
For instance, a device serialnumber field could contain the manufacturer'sserialnumber, an asset tag number issued by the organization that installs it, or something completely different.