however 的意思是「然而」通常是用在轉折語氣，前後兩句的意思是相反的
therefore 的意思是「因此」通常後面是接結果 前後是有因果關係的
It was raining; therefore, the game was postponed.
Moreover 的意思是「而且、再者」是後面的那一句補充前面那一句
I decide not to rent that flat. It's too small; moreover, the landlady is not very friendly.
如果克漏字要更進步，多寫題目增加語感是很有幫助的😊希望有幫助到你
