【简答题】E-R图中包括哪些基本要素?在E-R图具体用什么图形表示?
【判断题】有限差分法的基本思想是在偏微分方程中将偏微商用差商近似代替,得到差分方程。差分方程中未知数是有限的,可通过解差分方程得到微分方程的近似解。
【简答题】Dear Mr Fan, Yesterday I came across an interesting new book, which Iwould like to recommend here. It is an adventure story The title is Voyage to an Amazing kingdom. The publisher said that the novel...
【单选题】函数yx=A2x+8是下面某一差分方程的通解,这个方程是[ ].
【判断题】幼儿皮肤薄嫩,偏于酸性,保护功能差,易受损伤和感染。( )
【单选题】听力原文:Have you heard about an old book of the 19th century which sold for 300 thousand Euros last week? (A) I usually buy paperbacks rather than hardback ones. (B) It is really a best-selling one. (C) ...
【单选题】There is _______desk in the room. _______old book is on it.
【单选题】xt0506717在气相色谱法中,可用作定量的参数是()