Read the paragraph given below . Fill in the blanks by choosing the most appropriate words/phrases .
1. Perhaps the single greatest invention of the century is the computer . The computer is essentially a machine that enables humans to complete tasks that may be time consuming or very repetitive in nature . (a).....................it achieves by imitating human thought processes . In (b).....................the same way that humans think using pathways in their brains that conduct minute electrical currents, computers do this at an incredible speed.