20. ______we’ve devoted a lot of resources to locating the cause of this engineering problem, we’re still not sure we understand it very well.
(A)In spite of
(B) However
(C) Nevertheless
(D) Although

Although  we’ven devoted a lot of resources to locating the cause of this engineering nproblem, we’re still not we understand it very well.n

文法 : 兩個英文句子需要一個連接詞 

(A)In spite of +名詞或動名詞 (prep.)  儘管、雖然  --介係詞片語  句意相通但是文法不符合,所以不能選

(B) However 然而  --句意不符

(C) Nevertheless 然而  --句意不符

(D) Although +副詞子句 雖然(conj.)   --連接詞

20.________we’ve devoted a lot of resources to locating the cause of this engineering problem, we’re still not sure we understand it very well.

題目少了「sure」，請更正，謝謝您！

In spite of是介係詞，不能接完整子句

Although we’ve devoted a lot of resources to locating the cause of this engineering problem, we’re still not sure we understand it very well.

雖然我們已經投入了許多資訊來找出這個工程的問題，但我們仍然不確定我們對它的了解

本題按語意是要表達「雖然」或「儘管」，選項a.in spite of儘管和d.although雖然都符合，但空格後為子句而選項a必須接名詞，公式不合，故為d