Sam _____ some knowledge of the computer just by watching others working on it.[ ]

填入下面横线上的七句话，排序恰当的一组是西亚是亚洲西部的简称， ，在近代史上，西亚是西方和东方各民族文化交流的重要通道。①西亚处在欧洲、亚洲和非洲的交结地区。②它联结着地中海、黑海、红海、阿拉伯海和里海五个重要水域，被称为“五海之地”。③西亚是欧洲同广大亚洲和太平洋地区间的纽带。④古代有名的丝绸之路，就是通过西亚，把我国的锦缎运到古罗马。⑤13世纪意大利旅行家马可·波罗，也是通过西亚往返于北京和威尼斯之间。⑥自古以来，西亚就是亚、非、欧三洲之间交往的必经之途。⑦人们也把这一地区和埃及一起称为中东。

1There _______ amother ,a father and three children in the family.

―More than fifty students competed ________ each other in the composition competition.―But they could only compete________three medals.

It has the oldest castle ______ by later Norman rulers in 1066 [ ]