the guests(主语) had,of course(插入语),realized (谓语)this(宾语) from the moment Bessie opened the door for them(时间状语),and(连词) long before the final catastrophe(时间状语),had had (谓语)a difficult time(宾语) trying to conceal their asumement(主语补足语).
当然,在Bessie开门的时候,客人们就意识到了这一点,而且离最后的灾难很久以前,他们就已经为试着掩饰他们的asumement而痛苦一段时间。
had had a difficult time trying to conceal their amusement
这里是过去完成时态,第一个had 后面要就过去分词,所有第二个have 就变成了had,所有就有两个had , 这里had a difficult time 的原形是have a difficult time ,是指很难怎么样
首先 of course 和 long before the final catastrophe 都是这个句子中的插入语部分
这个长句的主语 the Guests 谓语 had realized 宾语 this
from 后面的一长串都是this的定语 而在这个定语中 又由the moment 作定语从句中的先行词 and 连接的两个动作 opened the door 和 had had a difficult time trying to conceal their amusement.
个人感觉 希望能够帮到你。。。