Products will be sent out tomorrow. (產品明天送出) Products will be sent out by tomorrow.(產品在明天以前送出) 兩者都可以。加一個by. 有強調"最後期限"的語氣。
send off = 寄出 send out = 放出
在參考書上看到這句Concrete jungles send out some of that heat,contributing to the higher higher temperature there . 此句為何要用現在分詞 contributing煩請告知感激不盡?
原句=Concrete jungles send out some of that heat, and they contribute to the the higher and higher temperature...