But in his weekly radio and Internet address, Mr.Obama cautions that much more work needs to be done to complete his planned overhaul of the health care system.

VOA: standard.2009.10.17

So the most basic answer that doesn't explain why is just to say well, the s orbital is lower in energy than the p orbital, but we now have a more complete answer, so we can actually describe why that is.

所以最基本的答案是那没有解释,所以我们事实上可以描述，为什么是那样，但是我们现在有一个更复杂的答案，又是有效电荷量。

麻省理工公开课 - 化学原理课程节选

So the most basic answer that doesn't explain why is just to say well, the s orbital is lower in energy than the p orbital, but we now have a more complete answer, so we can actually describe why that is.

所以最基本的答案是那没有解释,所以我们事实上可以描述，为什么是那样，但是我们现在有一个更复杂的答案，又是有效电荷量。

麻省理工公开课 - 化学原理课程节选