The diagram shows parts of a wave. A series of waves with an arrow passing through their centers. The highest point of one wave is labeled X. The lowest point of another wave is labeled Y. A bracket labeled Z connects the highest points of 2 waves. Which is shown by the letter X? trough amplitude crest wavelength

Consider a file currently consisting of 200 blocks. assume that the file control block (and the index block in the case of indexed allocation) is already in memory. calculate how many disk i/o operations are required for contiguous, linked, and indexed (single-level) allocation strategies, for each of the conditions listed below. in the contiguous-allocation case, assume that there is not room to grow at the beginning but there is room to grow at the end. also assume that the block information to be added is stored in memory.