68℃换算为开氏温度应是()。
A.339K
B.340K
C.341K
D.345K
参考答案:C
Linda's family in China.[ ]
A. live
B. living
C. lives
D. to live
若方程(x-1)(x2+8x-3)=0的三根分别为x1,x2,x3,则x1x2+x2x3+x3x1的值是( )
A.5
B.-5
C.11
D.-11