On hearing a great noise,MIkelookedforwardthroughthewindow__

On hearing a great noise,MIkelookedforwardthroughthewindow___ what happened outside the room.
A to seeing B to see
During the tourist season,there are many people wandering in this city to see the od castles __ inthe isxteenth century.
A to be built B being built C having been built Dbuilt
第一题为什么选B不选a 选A意思也通啊
第二题为什么么不选A去选D to be built修饰the old castles 为什么不行
They arrived there at last ,___
Awas tired and hungry B being tired and hungry C tried and hungry
为什么不选B啊分词being不是正确的吗