_____ I sympathize, I can't really do very much to help them out of the difficulties.
这里填While,为什么不能填as不也是表让步?
as 引导让步状语从句时,as不能放在从句的句首。如:
Child as he was, he knew what he was doing. 他虽然是个小孩,但很清楚自己在做什么。(有辨别力)(=Though he was a child, he ... )(摘自《英汉多功能词典》新编升级版p.92)
while 引导让步状语从句时,while 必须放在从句的句首。如:
While I sympathize, I can't really do very much to help. 虽然我很同情,但我帮不了大忙。(摘自《英汉多功能词典》新编升级版p.1941)