Operating systems are often written in , a very low-level computer programming language that allows the computer to operate quickly and

"Assembly language" is the correct answer for the above question.

Explanation:

Missing information :

The word after the and is missing which is "efficiently".

Detailed Explanation :

The assembly language is a low-level language that is used to operate the system or any controller or any system programming. The c language is also used for the purpose which is done by the assembly language but it comes in the categories of a high-level language.But some times the assembly language is used but this comes in the categories of a low-level language. So it is the correct answer for the above question because the question asked about the low-level language which is assembly only.

You click on it and type

B, it is easy to scan for key information. there are times when a lot of information is included in a business letter. the block letter format you find key bits of information quickly, without having to read through the whole paper.