The paper briefly introduces the history and development of the theoryofactivity teaching.
研究初中生物活动教学具有重要的理论与现实的意义。
2
Another flaw of the tiredness theory is that yawning does not raise alertness or physiological activity, as the theory would predict.
疲劳理论的另一个缺陷是，打哈欠并不能像该理论所预测的那样，提高警觉性或生理活跃度。
3
Certainly, some of the facts at hand are valid; for example, the Maya did have a Long Count calendar, pole-shift theory does exist, and solar activity does wax and wane.