英文 從屬連接詞？

(a) now that -- 現在(已)
eg. Now that the examination is over, I can have more time for my leisure.
現在(由於) examination 已完結, (因此) I can . . .
若寫成 :
Seeing that the examination is over, I can have more time for my leisure.
則句子「不太適合」--因為 “examination is over"並不需要 察覺到！

(b) seeing that -- 眼見/察覺到
eg. i) Seeing that Bobby has enough, he takes away the dog’s food bowl.
　　眼見/覺得 Bobby已經吃夠了, (所以) 他拿走the dog’s food bowl.
若寫 ii) Now that Bobby has enough, he takes away the dog’s food bowl.
意思會變為 :
　　現在Bobby已經吃夠了, (所以) 他拿走the dog’s food bowl.

Conclusion:-
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用Now that或 Seeing that在某一句子上, 意思會有差別;
有些用兩者都可以-- like (b), 但有些卻應採用其中一款-- like (a)！
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(c) seeing as -- 視為
eg. Seeing his car as his wife, he won’t lend it to anybody.
他把車子視為太太, . . .
“seeing as” 與 “seeing that” 意思完全不同！

Dependent connective word "now" adv.:-
"now that":-conj.
eg:-used as a consequence of the fact that
-----Now that you mention it, I do remember you are a bad boy.----"because"
eg:-Now that you are grown up, you must pay the senior fees.---"so that"
seeing that:- in view of the fact that; "considering;"
eg:-Seeing that it is a murder case, you must be careful on your safety outside---"so that."
eg:-Seeing that you are weak, you know you must keep fit by exercising.---"because"
Seeing as:-as the result of a something after you have done something:-
The Direct object is followed by a noun introduced by "as"
S + vt----+DO-----+as+noun
eg:-I can't "seeing" myself "as" a pop star TVB.
eg:-Undergrads "seeing" duty "as" a calling morality in their conscience.
eg:-"Seeing" your GF "as" a Filipino maid.
eg:-Parents "seeing" her "as" a baby.
Also seeing as may be used in same as regard as; view as, represent as, treat as, acknowledge as, so as to introduce an object.
eg:-Having caught in the riot, you're "seeing as" a criminal----"because."
eg:-All undergrads.are "seeing as" a junior by you.----"so that"