以下选择器书写正确的是（）。 A: $（"#a a"） B: $（"a：password"） C: $（"a.a1"） D: $（"a：even"）

若有定义语句：structa{inta1;inta2;};structaa3;以下赋值语句正确的是（） A: a.a1=4; B: a2=4; C: a3={4,5}; D: a3.a2=5;

设向量组A1,A2,A3线性无关,则下列向量组中线性无关的是（）A.A1,A2,A1+A3B.A1,A2,A1-A2C.A1－A2,A2-A3,A3-A1D.A1+A2,A2+A3,A3+A1

设向量组A1,A2,A3线性无关,则下列向量组中线性无关的是（）A.A1,A2,A1+A3B.A1,A2,A1-A2C.A1－A2,A2-A3,A3-A1D.A1+A2,A2+A3,A3+A1

国家标准中规定的图纸基本幅面代号有：A.A1、A2、A3、A4、A5B.A0、A1、A2、A3C.A0、A1、A2、A3、A4、A5D.A0、A1、A2、A3、A4 A: A B: B C: C D: D

for i in range(b.max_row): for j in range(b.max_column): print(b.cell(row=i,column=j).value)上面语句运行的结果是：__________。 A: 1 1 1 1 1 1 1 1 1 1 B: 1111111111 C: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 D: 出现异常

【单选题】CDMA通信的基站,假定基站A的码片序列是+1 +1 +1 -1 -1 +1 -1 -1,基站发射bit为101时,实际发射的信号是 A. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 B. +1 +1 +1 -1 -1 +1 -1 -1 –1 –1 –1 +1 +1 –1 +1 +1 +1 +1 +1 -1 -1 +1 -1 -1 C. +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 +1 +1 +1 -1 -1 +1 -1 -1 D. –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1 –1 –1 –1 +1 +1 –1 +1 +1

【单选题】下列常用图纸幅面对应的图框尺寸, 错误 的是 A.A1 图纸尺寸为 594×841 B.A2 图纸尺寸为 420×594 C.A3 图纸尺寸为 420×210 D.A4 图纸尺寸为 210×297 A. A1 图纸尺寸为 594×841 B. A2 图纸尺寸为 420×594 C. A3 图纸尺寸为 420×210 D. A4 图纸尺寸为 210×297

for i in range(1,11): for j in range(1,11): b.cell(row=i,column=j).value=1 #b是一个工作表对象for i in range(1,11): for j in range(1,11): print(b.cell(row=i,column=j).value,end=" ") print()上面程序代码运行的结果是（）。 A: 1 B: 1 1 1 1 1 1 1 1 1 1 C: 1111111111 D: 1 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1

下列哪个码片序列不能用于CDMA通信 A: ( -1 -1 -1 +1 +1 -1 +1 +1 ) B: ( -1 -1 +1 -1 +1 +1 +1 -1 ) C: ( -1 +1 -1 +1 +1 -1 -1 -1 ) D: ( -1 +1 -1 -1 -1 -1 +1 -1 )