____, he does not know the answer.

依次填入下列横线处的词语，最恰当的一组是中华民族是个与石头有着不解之缘的民族，中国的石头文化 。追溯到八千年前，先民已经在玩玉石了。人们对玉石的 催生了“黄金有价玉无价”的观念，进而 为“谦谦君子，温润如玉”的石文化。中国人爱石，将石当作朋友， 当作自我生命的象征，以石来抚慰心灵，通过石头来看宇宙人生的大道理。

Mike, is this your eraser — No, it’s not ______. Maybeit’s __________.

______he was exercising at the park yesterday morning, he found a purse under the tree.

It was believed that things would get worse, but _____ it is they are getting better[ ]