Mid-morning is usually good for me.

已知三阶矩阵$A$满足$\mid A-E\mid=\mid A-2E\mid=\mid A-3E\mid=0$，则$\mid A\mid$=( )。 A: $4$ B: $6$ C: $12$ D: $3$

设$A,B$是$n$阶正交矩阵，且$\mid A\mid=-\mid B\mid$，则( ). A: $A+B$可逆 B: $A+B$不可逆 C: $\mid A+B\mid=1$ D: $\mid A+B\mid=-1$

【单选题】Firemen discovered the cause _________. A. today morning B. today in the morning C. in the morning today D. this morning

Excel2010从18份身份证号中获取出生日期可以使用（）函数。 A: MID(A1,6,8) B: MID(A1,7,8) C: =MID(A1,6,8) D: =MID(A1,7,8)

船舶电台海上移动业务识别码的组成是( )。 A: MID X1X2X3X4X5X6 B: 0 MID X1X2X3X4X5 C: 00 MID X1X2X3X4 D: 00 MID X1X2X3X4X5

如果A1单元格中有某人的身份证号，如何提取他的出生年月日 A: mid（A1,7,4） B: mid（A1,4,7） C: mid（A1,7,8） D: mid（A1,8,7）

________he went to New York . A: On the next day morning B: On the next day’s morning C: In the next day’s morning D: On the morning of the next day

11.She went to the countryside ______.　　a. in the morning at nine on June first,1968 b. on June first,1968 in the morning at nine　　c. at nine in the morning on June first,1968 d. on June first,1968 at nine in the morning A: in the morning at nine on June first,1968 B: on June first,1968 in the morning at nine C: at nine in the morning on June first,1968 D: on June first,1968 at nine in the morning

strpos("good morning","morning")的返回值是