幾個英文文法的疑惑?

1. Coco wants a job ____ can grant her the opportunity to be in contact with celebrities and prestigious producers.
答案是that 為何不能用which?

這題的空格可以用that或which。兩者都是限定性質的關係代名詞。請參見柯旗化《新英文法》p.98 that的用法。

2. ＿_Mr. Muller was talking to his nutritionist, his wife interrupted and complained about his bad hygiene.
(A)While (B)As
答案是(B)As 為何不能用While ?

前面子句的動詞是「過去進行式」表示一直在發生中（一條線），但後面的子句是「過去簡單式」（一個點），所以不能用表示同時進行的while（有兩條線），而要用表示「原因」的as。

3. Tim's scratch on his ankle is infected ____ he wore slippers to the garden, and the bacteria in the mud got into his foot.
(A)because (B)as
答案是(A)because 但我記得As不也可用來表示原因 但這裏為何不行？

because, since, as都可以引導表示原因的副詞子句。明確指出原因為何時，用because。如果認為閱聽者應該已經知道原委而提出理由（非新訊息），或所提理由為次要訊息時，就會用since/as。(請參見p.340綿貫陽《新觀念英文法》。
本句是前者的狀況。所以用because.



3.還有that 可以引導名詞子句感覺和複合關代what好像 但又不能都通用的樣子 搞得我好亂
像是這句
The report indicated____ there is excessive waste from the plant, and a warning was issued accordingly.
這空格就要用that 為啥不能用what?
然後這句Julia hesitated to explain what she had really meant to say.不知這裏的what可不可以用that替代？

第二句這裡的what是「關係代名詞」，what = the thing that...（先行詞＋從屬連接詞），所以不能只以一個「從屬連接詞」that來代替。
第一句裡的that是「從屬連接詞」，引導從屬的名詞子句。
但「關係代名詞」在附屬子句兼「主詞」或「受詞」。
His wild speech was what frightened us away.（what兼附屬子句的主詞）
George made it clear what he wanted.（what兼附屬子句的受詞）

that:-
The report indicated
that there is a war on trees------introducing clauses of result purpose, condition.

what;
Ask Julia
what she meant in her Q .----------n. cl. in apposition.

(1)definite rel.pron.
(2)past condt+ past tense=As儘管.
(3)because因為原委原因.
(4)not (3)?---that------>rel.conjunc
-----------------what----->rel.pron