补全对话, 其中有两个多余选项。

(D=Darren, C=Carol)

D: Hi. Carol! ____

C: Oh, hi, Darren. I’m just getting ready for the Red Nose Day concert tomorrow.

D: Oh, really? Well, I’m free this afternoon. ____

C: Actually, I’ve nearly finished. Jim and I are going to put up some ads later, though. Could you please help us with that?

D: ____

C: That’s wonderful! Oh, there’s one more thing. Would you mind coming early tomorrow to help sell tickets at the door?

D: Not at all. ____

C: Around six would be great.

D: OK. ____

C: Great.

①遵循事物发展的客观规律        ②抓住主要矛盾的主要方面

③不失时机地促成质的飞跃        ④坚持普遍性与特殊性的统一

我们把$\left|\begin{array}{cc}a& b\\ c& d\end{array}\right|$称作二阶行列式，规定他的运算法则为$\left|\begin{array}{cc}a& b\\ c& d\end{array}\right|$=ad﹣bc，如：$\left|\begin{array}{cc}2& 3\\ 4& 5\end{array}\right|$=2×5﹣3×4=﹣2，如果有$\left|\begin{array}{cc}2& 3-x\\ 1& x\end{array}\right|$＞0，则____