果蝇的性染色体构型是XY型,所以果蝇的性别是由Y染色体决定的。()
参考答案:错
People may have different opinions about Karen, but I admire her.___, she is a great musician. [ ]
A. After all
B. As a result
C. In other words
D. As usual
A.条件(1)充分,但条件(2)不充分.
B.条件(2)充分,但条件(1)不充分.
C.条件(1)和(2)单独都不充分,但条件(1)和条件(2)联合起来充分.
D.条件(1)充分,条件(2)也充分.
E.条件(1)和(2)单独都不充分,条件(1)和条件(2)联合起来也不充分.
x,y∈R,则|x|+|y|=|x-y|. (1)x>0,y<0; (2)-x<0,y>0.