这是玛利亚的书。

This is the book ___of Maria.

这把椅子是用木头做的。

This chair is made ___of wood.

我们昨天就环境保护问题进行了详细讨论。

We had a detailed discussion ___on environmental protection yesterday.

大部分的蛋糕都被吃完了。

Most ___of the cake was eaten.