_______ is even important is ______ as the earth cooled down, water began to appear on its surface.

Water, which seems so simple and common, is ______ makes life possible.

I'm afraid he’s more of a talker than a doer, which is ____ he never finishes anything．  

 The reason________ Peng Liyuan is widely discussed recently is ________ she is seen as the most beautiful first lady in China.

        others think about you isn’t important. The key is        you should be self confident.