The Chinese invented block printing more than 1,400 years ago. The original characters were carved on wood and ink was then applied. Block printing is time consuming and ___61___ ( cost) a lot of manpower and materials. Misprinted characters cannot be ___62___ ( easy) corrected. These shortcomings were only overcome after the appearance of movable type printing, ___63___ greatly improved the speed and quality of printing.
Bi Sheng of the Northern Song Dynasty invented the movable type printing. He carved the Chinese characters on small ___64___ (cube) of sticky clay. He baked them in the fire until they became hard and movable. In the course of presswork, the movable characters were placed into ___65___. iron frame until it was full. He then took a smooth board and pressed it over the surface so that the block of type became even: Then ink was applied and it was ready ___66___ printing. To be more ___67___ (efficiency),he prepared two iron boards. When one was being used for printing, the other could be used ___68___ (put) characters in order for the next page. The two boards were used alternately.
Although what Bi Sheng invented was simple when ___69___ (compare) to today's letterpress printing; it already bad the main traits of modem printing. So Bi Sheng's _____70_____ (contribute) to printing cannot be overstated.
【答案】61. costs 62. easily 63. which 64. cubes 65. an 66. for 67. efficient 68. to put 69. compared 70. contribution