多益練習題求解,關於文法?

1. You may leave early today since you report early tomorrow.
未來的事一般是不確定的，如果確定的話，可以用「現在簡單式」。
如Mr. Robinson retires at the end of the year.
p.88 綿貫陽《新觀念英文法》
你明天會早來是「確定的」，所以我核准你現在可以早退。

其它用現在式代替未來式的狀況如下：
come, go, start, leave等動詞和表示未來時間的副詞連用時，用現在式代替未來式：
Do you come tomorrow?
I start (or leave) tomorrow evening.

在表示時間或條件的副詞子句(if ~, when ~, before ~, after ~, till ~, as soon as ~等），用現在式代替「無意志未來式」。
If it rains, I shall not go.
When he comes, please tell him to wait.

If he comes, give him this book.
If he will come, we shall be very happy.（意志未來：如果他願意來......）

2. It is my pleasure today to announce a decision that "we hope" will facilitate banking business for customers outside California.
we hope是插入短語，作者用來加註解或評斷，評論等（我們希望能夠得到那樣的結果），與全句的句構無關。形容詞子句that will facilitate banking business for customers outside California是修飾先行詞decision的限定性質的修飾語。
類似的插入短語：My mother, whom "I'm sure" you remember, passed away last year.插入短語I'm sure
What "do you think" is your biggest fault?插入短語do you think

(1)You may leave work early today(since) you report early tomorrow.(since) is usually followed by a time expression,Or by a clause in the present tense,not future=will report.
Leave work early today---->report early tomorrow.<------->both uses are correct for using "since".
(2)To announce a decision that we hope----
--------that will facilitate-------
"that" is often left out when it is the object of the verb(hope) in the relative clause"that will facilitate
------->Hence(that) will facilitate---->will facilitate.
With best of wishes.

1. 關鍵是since有兩種解釋或用法(意思)，比較一般的意思是"指時間的關係"，由一個時間至另一個時間的時段或某時間"開始"計算....；但另一個意思是"因為"或"由於"。
這句的答案似乎原句子的講法意思答since是因為句子前後句的關係不是"時間"而是"理由"。

因為你明天是會提早上班(可能是預早已知的安排)，所以現在今天"你可以提早離開(放工)"
但是假如這個人並不是預知/安排是明天早返工的編排，而這個上司是"現在"才特別關照或作出批准而提出"補償"性的安排是"你明天要提早返工"的話，則答案D亦是可以/常見的說法(尤其是當英文前句說"you may"這個may是可以指"未確定的條件之下才會實行"的意思，所以我會說You may leave early today only if you report early tomorrow.會較You may leave work early today since you report early tomorrow. 假如是答案所指的since表示這上司說這句是因為已知他明天早返工的安排的話，他的句子應該是You can leave work early today since you report early tomorrow.
當然如何所說明天未知的話文法上理應是you will report，因此邏輯即是說"you report (to work) early tomorrow是已知的事。

It is my pleasure today to announce a decision that we hope will facilitate banking business for customers outside California.絕對是口語省略不少"文法"而成的句子。假如全寫/講可以是
It is my pleasure today to announce a decision that we hope that we will facilitate banking business for customers outside California.
因此作者/講者便把自己重復的that we自行省去，結果是一句怪怪的英文句子(就算以英語口語規格而言也不對的)。但就分析而言，"hope"和"facilitate"都是we想做到的動詞內容。