1.a beam of (light) 一束（光）

例句:Reflection of a beam of light on the diaphragm falls on a phototransistor.
經(jīng)膜片反射的光束照射到光敏管上。

2.a big shot 大人物

例句:He acts like a big shot, but he is just a small potato.
他行事象個大人物,但實際上他卻微不足道。

3.a big sale 大減價

例句:Lose no time in buying a real bargain at the big clearance sale.
趁清貨大減價，快買便宜貨。

4.a bunch of 一束，一串，一群

例句:He produced from his pocket a bunch of keys.
他從口袋里掏出一串鑰匙。

5.a cloud of 一大群；一大片

例句:A cloud of suspicion still hung over the White House.
白宮上空仍籠罩著一團疑云。

6.a couple of 一對，一雙；幾個

例句:Selection is a pretty simple concept, but there are a couple of basic variants worth discussing.
選擇是相當簡單的一個概念，但有一些變體值得我們來討論。