教堂塔楼上有一个时钟。

There's a clock on the church ___tower.

他在旧金山市中心的一栋办公大楼工作。

He works in an office ___tower in downtown San Francisco.

我认为，首先我们应该参观我们的首都，因为它有许多古老的塔楼、城堡和教堂，你必须看看。

I think that, first of all, we should visit our capital because it has many old ___towers, castles and churches, which you have to see.