1. If the Administration won’t take the legislative initiative, Congress should help to begin fashioning conservation measures.
take the initiative：习语。“采取主动” = “首先采取行动”
take the legislative initiative：在立法上首先采取行动
【翻译】如果政府在立法上不采取主动（=不首先采取行动），国会应该帮助制定保护措施措施。

2. If we are ever going to protect the atmosphere, it is crucial that those new plants be environmentally sound.

划线部分为主语从句，从句中省略了should。it 为形式主语。

it is crucial that those new plants should be environmentally sound.

这是虚拟语气用于主语从句中。谓语动词用“should + 动词原形”，should可以省略。

基本结构是： It is important...that (should) 原形。

与这类形容词有关（表示“必要、必须、重要等意义”），necessary, appropriate, proper, right, essential, vital, natural, crucial （至关重要的）等。

  It is very important that one（should）master the skills of computer.