重點講解：
1. perch on 棲息；在較高或較險的位置
例句：Tall buildings perch on the top of rocky cliffs.
高聳的建筑屹立在嶙峋的懸崖頂上。

2.rain down 如雨般落下
例句：If one Ford works as planned, a series of benefits will rain down on the company and its suppliers.
如果Ford一體化如計劃般展開，一系列的盈利就會降臨到公司和供應商頭上。

3.form into 組成；編成
例句：The single piece of DNA molecule winds itself around special proteins to form into very tight coils like a string (shown in yellow).
這個一段DNA分子把自己彎曲在特殊的蛋白質周圍而形成非常緊的卷如一段弦一樣（如黃色部分所示）。

4.pull apart 扯斷(索子等)；勸開
例句：These pieces of ice don't pull apart easily.
這些冰塊不易分開。