the guests（主語） had,of course（插入語）,realized （謂語）this（賓語） from the moment Bessie opened the door for them（時(shí)間狀語）,and（連詞） long before the final catastrophe（時(shí)間狀語）,had had （謂語）a difficult time（賓語） trying to conceal their asumement（主語補(bǔ)足語）.
當(dāng)然,在Bessie開門的時(shí)候,客人們就意識(shí)到了這一點(diǎn),而且離最后的災(zāi)難很久以前,他們就已經(jīng)為試著掩飾他們的asumement而痛苦一段時(shí)間.
had had a difficult time trying to conceal their amusement
這里是過去完成時(shí)態(tài),第一個(gè)had 后面要就過去分詞,所有第二個(gè)have 就變成了had,所有就有兩個(gè)had ,這里had a difficult time 的原形是have a difficult time ,是指很難怎么樣