【判断题】任何糖类化合物在体内都可水解成葡萄糖 ( )
【判断题】一台三相电动机,每相绕组的额定电压是220V,三相电源的线电压是380V,则这台电动机的绕组应接成三角形。
【单选题】--- What does the notice on the wall say? --- ‘No person take books out of the reading room; otherwise he would be fined.’
【简答题】已知椭圆 x 2 25 + y 2 16 =1 与双曲线 x 2 6 - y 2 3 =1 在第一象限的交点为P,则点P到椭圆左焦点的距离为______.
【单选题】Narrating is bound to promote learning because_________
A.
it makes the otherwise obscure experience prominent in one's mind
B.
it helps one to lay down one's emotional burden
C.
it enhances memory by repeating things before one forgets them
D.
it helps add more details to what is already in memory
【单选题】设P为双曲线 x 2 9 - y 2 16 =1 上的一点且位在第一象限.若F 1 、F 2 为此双曲线的两个焦点,且且|PF 1 |:|PF 2 |=3:1,则△F 1 PF 2 的周长等于( )