15. Thanks to modern irrigation, crops now grow abundantly in areas where once nothing but cacti and sagebrush could live.
15.受当代灌溉(技术设施)之赐，农作物在原来只有仙人掌和荞属科植物才能生存的地方旺盛的生长。
16. The development of mechanical timepieces spurred the search for more accurate sundials with which to regulate them.
16.机械计时器的发展促使人们寻求更精确的日晷，以便校准机械计时器。
