比原子序数为11的元素原子少1个电子而又多1个质子的微粒是（）
A.Na+
B.Na
C.Mg2+
D.Mg
E.Mg+
参考答案：C
一次函数y=-x+1与x轴，y轴所围成的三角形的面积是______．
----What did the young man come to your company for?
--- He wanted a job, _______could help him support his family.
A．what
B．one
C．that
D．one that
