I wonder _____ there are so many natural disasters across the world. [ ]

A. why is it that

B. what is it that

C. what it is that

D. why it is that

政治博弈分为（）两大类。

A.零和博弈

B.正向博弈

C.负向博弈

D.双赢博弈

E.非零和博弈