15.The space shuttle Columbia broke into pieces over Texas as it returned to the earth on February1,2003____,all seven astronauts aboard.
A.having killed B killing C being killed D.killed
16.---____the he managed to get the information?
----Oh ,a friend of his helped him.
请对每个选项进行分析
最好翻译一下
16题的选项A.Where was it B. What was it C. How was it D.Why was it
