Engineers spent many months ______ the software.
举一反三
- Software is often divided into application software and system software.
- The help function of the software can make the users who contact the software quickly understand the software, which is one of the necessary functions of the software.（ ）
- I spent two months on the book.It ______ ______ two months ______ ______ the book.
- The engineers spent the whole night(work) ___________on the new device.
- Human beings also have hardware and software. __________ is to human beings what software is to computer.