瓦斯的（）对煤矿危害最大。
A、扩散性
B、难溶于水
C、不助燃性
D、燃烧爆炸性
参考答案：D
存款5000元，一年定期存款的年利率是3.87%，一年后应得税后利息______元．
Some people believe _______ has happened before or is happening now will repeat itself in the future.
A．whatever
B．whenever.
C．whereever
D．however
