短語學習：

1.back and forth: 反復地，來回地

eg. Switching between these states allows Grier to move objects back and forth.
格里爾通過轉換這些狀態來實現向前和向后移動物體。

eg. Negotiating is the process of communicating back and forth for the purpose of reaching an agreement.
談判是為了達成協議而反復交流的過程。 它包括說服和妥 協。

eg. The pendulum swings back and forth.
這就像單擺一樣來回擺動。

2.big time: 巨大成功；大范圍地；愉快的時光；第一流

eg. I owe you big time.
我欠你一個大人情。

eg. This was the magical moment, his entrance into the big time.
這是一個創造奇跡的時刻，是他走向大成功的開端。

eg. When the pressure in the big time got to be too much, the guy simply returned.
當來自上面的壓力太大時，這家伙干脆甩手不干了。

2.used to: 過去常常

eg. I'm not used to getting up early.
我不習慣很早起床。

eg. You will soon become/get used to the weather here.
你很快就會習慣這里的氣候。

eg. I used to do business with him.
我過去和他常有業務往來。

3.better off: 情況更好

eg. We have to do that now, because it will actually make our businesses and our families better off.
我們現在得行動了，因為那樣事實上會讓我們的企業和家庭更美好。

eg. If your income doubles but the prices of the goods you consume also doubles, you are no better off.
如果你的收入翻番，但所消費商品的價格也翻番，你就沒有變得更富裕。