A:been dead; was killed
B:died; was killed
C:been dead; killed
D:died; killed
hé:____
fǎng:____
mù:____
yuè:____
jìng:____
dào:____
已知α、β是关于x的一元二次方程x2+(2m+3)x+m2=0的两个不相等的实数根,且满足1α+1β=-1,则m的值是____
云无心以出岫,____。(陶渊明《归去来兮辞》)
下列粒子结构示意图中表示阴离子的是( )