可推测pfizer可于多年之前向患病儿童提供此药，却决定等到现在推行此药。

Presumably Pfizer could have offered the drug to sick children years ago, but decided to wait until now to move forward with it.

youdao

我希望留下，如果切尔西希望找人替换我的话，那他们就不会等到现在了。

I want to stay - and if Chelsea had wanted to make a change, they would have done it by now.

youdao

So, that's going to be important later when we get to bonding, but just take note of it now, we have two nodes, or we have two lobes, excuse me, each with a separate phase.

这等到我们之后讲到成键时是非常重要的，现在先要记住，我们有两个节点，不好意思，是两个叶瓣，每个都是不同的相位。

麻省理工公开课 - 化学原理课程节选