20.在凱因斯模型中，出現「流動性陷阱」通常意味著： (A)貨幣供給完全固定 (B)貨幣需求對利率極具彈性 (C)利率對投資完全無彈性 (D)政府支出乘數為零

3. Which of the following is not determined by the principal quantum number, n, of the electronin a hydrogen atom?(A) the minimum wavelength of the light needed to remove the electron from the atom.(B) the energy of the electron(C) the shape of the corresponding atomic orbital(s)(D) the size of the corresponding atomic orbital(s)(E) All of the above are determined by n.