1.upon receipt 一旦收到

Quotations and samples will be sent upon receipt of your specific enquires.
一收到你方的具體詢盤，我方將馬上寄送上報價和樣品。

Establishment of service is reliant upon receipt by the Company of payment of affirmed charges.
建立服務是依賴于收到該公司支付的費用肯定。

Order may only be processed upon receipt of full payment and refund will not be accepted in any cases.
本公司只處理已收妥所有款項的訂單，并在任何情況之下都不接受退款。

2.L/C abbr. 信用狀（letter of credit）

An irrevocable and transferable L/C.
不可撤銷的，可轉讓的信用證。

As for payment, we prefer an irrevocable L/C.
至于付款條件，我方希望開立不可撤銷的信用證。

For large orders, we insist on payment by L/C.
對于金額大的訂貨，我們便要求開信用證。

3.rather difficult 相當困難

To be a good engineer is rather difficult.
要做一個好的工程師是相當困難的。

I found her rather difficult to work with .
我發現很難和她共事。

This book is easy, but that one is rather difficult.
這本書容易讀懂，但那本很難讀。

4.out of stock adv. 已脫銷

These boots are out of stock right now.
這雙靴子目前缺貨。

Sorry, king sized shirt is out of stock now.
不好意思，大號的襯衫現在沒貨。

This item is out of stock, but it is on order.
這項產品全部售空（已無存貨），但已經訂購了。