Read the passage and answer the question: Why is literacy so important in the modern world? Some of the reasons, like the need to fill out forms or get a good job, are obvious. But the chief reason is broader. The complex undertakings of modern life depend on the cooperation of many people with different specialities in different places. Where communications fail, so do the undertakings. The function of national literacy is to foster effective nationwide communications. Our chief instrument of communication over time and space is the standard national language, which is sustained by national literacy. Mature literacy alone enables the tower to be built, the business to be well managed, and the airplane to fly without crashing. All nationwide communications, whether by telephone, radio, TV, or writing, are fundamentally dependent upon literacy, for the essence of literacy is not simply reading and writing but also effective use of the standard literate language. — 'complex undertakings of modern life' means: