首先倒装,理顺了就是we take increased devotion to that cause （for which they gave the last full measure of devotion 修饰cause其中的they指的是these honored dead ） from these honored dead
破折号后面的长句,结构不是很明了,括号里面的
首先倒装,理顺了就是we take increased devotion to that cause （for which they gave the last full measure of devotion 修饰cause其中的they指的是these honored dead ） from these honored dead