翻译：我们已经收集了将近100000套被子,多达一半（的被子）已经运往洪灾地区.
此题考查非限制性定语从句的关系词和先行词用法.
1.先行词为100000 qulits,将其代入后面的定语从句中,变化为：
(of which) up to half have gone to the flooded -hit areas
= up to half (of which) have gone to the flooded -hit areas
= up to half (of the 100000 qulits) have gone to the flooded -hit areas
句意为：这100000套被子的多达一半已经送往洪灾地区
up to意思是“多达...”.
2.能直接代替先行词100000 qulits,指物并用在非限制性定语从句中的关系代词只能用which.
英语语法中,如果关系代词在定语从句中充当介词（本题是of）的宾语时,经常把这个介宾短语一起提前至定语从句的句首.