一物体质量为10 kg，受到方向不变的力F=30+40t(SI)作用，在开始的两秒内，此力冲量的大小等于________________；若物体的初速度大小为10 m/s，方向与所受力同向，所受力F=30+40x(SI), 则物体在从x=0移动到x=10m的过程中，物体的速度的大小等于___________________． A: -140 N·s； -29 m/s B: 140 N·s；29 m/s C: -140 N·s ; -24 m/s D: 140 N·s ; 24 m/s

光纤的外径一般为（），它是利用光的全反射原理来传光的。 A: 125～140μm B: 126～140μm C: 125～141μm D: 124～140μm

道岔基本轨与滑床板、轨撑的连接螺栓牢固，扣件全、正、紧、靠扭力矩达到（） A: 80~150N.m； B: 70~140N.m C: 80~140N.m

For the concrete pavement with slab of 25cm, the temperature gradient is ______℃/m if the temperatures for the top surface and bottom surface of the slab are 35℃ and 15℃, respectively. A: 80℃/m B: 140℃/m C: 60℃/m D: 140℃/m

交换m,n数值的方法 A: m,n=n,m B: n,m=m,n C: m,n=m,n D: n,m=n,m

【单选题】如果m>0,n<0,m<|n|,那么m,n,-m,-n的大小关系是() A. -n＞m＞-m＞n B. m＞n＞-m＞-n C. -n＞m＞n＞-m D. n＞m＞-n＞-m

某天体赤纬DeC A: 35°N；220°W B: 35°S；140°W C: 35°S；140°E D: 35°N；140°E

求给定自然数m和n的最大公约数。请完善程序。 Private Sub Command1_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r Do r = m Mod n m = n n = r Loop Until__________ Text3.Text = m End Sub Private Sub Command2_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r r = m Mod n Do Until _______ m = n n = r r = m Mod n Loop Text3.Text =____ End Sub Private Sub Command3_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r Do r = m Mod n m = n n = r Loop While________ Text3.Text =______ End Sub Private Sub Command4_Click() Dim m As Integer, n As Integer, r As Integer m = Text1.Text n = Text2.Text If m < n Then r = m: m = n: n = r r = m Mod n Do While______ m = n n = r r = m Mod n Loop Text3.Text =____ End Sube73f1fd63959cc8362d8c82d419c2353.png

设A与B为矩阵,AC=CB，C为m×n矩阵，则A与B分别是( )矩阵‎‏‎ A: n×m,m×n B: m×n,n×m C: n×n,m×m D: m×m,n×n

求极限[img=144x45]1803d6afb8a008a.png[/img]的MATLAB程序为：syms x m n ay=(x^m-a^m)/(x^n-a^n)limit(y,x,a)计算结果为： A: (a^(m - n)*m)/n B: a^(m - n)*m/n C: 无法求值 D: a^(m - n)*m*n E: a^(m - n)/m/n F: (a^m - n)*m)/n