Complete the text with suitable prepositions.
Email has brought (a) ______ a revolution (b) ______ modern communication. Messages can be transmitted (c) ______ one country to another (d) ______ seconds. It is far cheaper than telephone calls. Trade and commerce have become greatly dependent (e) ______ this speedy mode (f) ______ communication. It has, however, not reached everyone, especially (g) ______ developing countries (h) ______ ours, as most people cannot afford (i) ______ have a personal computer. But even here, people have started using commercially operated email facilities (j) ______ important purposes.