I didn't understand why it had to take fifteen years to make a military satellite," she said."You could see my interest was waning"
1. if something such as power, influence, or a feeling wanes, it becomes gradually less strong or less important:
例：The group’s influence had begun to wane by this time.
造句：My interest for the project was waning.
2. when the moon wanes, you gradually see less of it
反义 wax 中秋节快到了，可以用上这两个表示月亮阴晴圆缺。
短语：wax and wane (= grow and then decrease) 盛衰:
Public interest in the issue has waxed and waned over the years.
He would trap an enginner in the SpaceX factory and set to work grilling him about a type of valve or specialized material.
[transitive] to ask someone a lot of questions about something
同义： question/pepper somebody with questions（前几天学过的）
grill somebody about/on something
例：She never grilled her husband about his work.
造句:My friend is afraid of being grilled by his parents.
But as SpaceX hire one brilliant person after another, Musk realized he could tap into their stores of knowledge.
to use or take what is needed from something such as an energy supply or an amount of money:开发；开辟；着手利用
例：People are tapping into the power supply illegally.
If you have a store of knowledge, jokes, or stories, you have a large amount of them ready to be used. 大量;丰富
【搭配模式】：usu N of n
例：He possessed a vast store of knowledge...他知识渊博。
造句：He possessed a store of money.
It's one of his most impressive and intimidating skills and seems to work just as well in the present day as it did when he was a child vacuuming books into his brain.
After a couple of years running SpaceX, Musk had turned into an aerospace expert on a level that few technology CEOs ever approach in respective fields.
He doesn't say,'You have to do this by Friday at two P.M."He says,"I need the impossible done by Friday at two P.M.Can you do it?Then, when you say yes, you are not working hard because he told you to. You're working hard for yourself.