(2014·安徽省芜湖三校一模)A recent study has  ________an unexpected conclusion that the African elephant should be divided into two different species.

A．kept up with 　

B．made up with

C．caught up with　

D．come up with

写出下列反应的符号表达式，并在括号中注明反应的基本类型．

（1）硫在空气中燃烧______

（2）过氧化氢溶液和二氧化锰混合制氧气______．