单选题 Just as there are many different 26 in use throughout the world for humans to communicate with, there are different languages that are used to communicate with a computer. Programming languages, in computer science, are the 27 languages used to write a sequence of instructions (a computer program) that can be run by a computer. They are standardized communication technique for expressing instructions to a computer. 28 natural languages, such as English, programming languages have a vocabulary, grammar, and syntax. However, natural languages are not suited for programming computers because they are 29 , meaning that their vocabulary and grammatical structure may be interpreted in multiple ways. The languages used to program computers must have simple logical structures, and the rules for their grammar, spelling, and punctuation must be precise. They enable a 30 to precisely specify what data a computer will act upon, how the data will be stored or transmitted and precisely what actions to take under various circumstances.