【简答题】“I could have told him all this, but it was fairly obvious he wasn't going to be around long enough for it to matter.” please explain what meaning of "it" in the sentence above.
【单选题】u and i are generally function of time, the power p in Eq. (p=ui) is a time-varying quantity and is called the instantaneous power. What does the phrase "instantaneous power" in the sentence above mea...