单个证券的风险一收益特征一般是不会随时间推移而产生变化的。()
参考答案:错
解析:每一证券都有自己的风险一收益特性,而这种特性又会随着各相关因素的变化而变化。
Tom is a worker. He _____ in a factory. His sisters _____ in a hospital. [ ]
A. work; work
B. works; works
C. work; works
D. working; working
1-2+3-4+5-6+7-8+……+1989-1990+199l=( )
A.895
B.896
C.995
D.996