go sightseeing 观光旅游招待
a: what about visiting the great wall this weekend? the weather is great tomorrow.
b: that's a good idea.
c: great.
b: could you introduce it for us?
a: ok! the great wall is one of the wonders of the world. and nowadays it acts as not a defense against the offensive, but the precious historical relic which welcomes tourists from all over the world. and we'll know more about it through the guide's introduction.
b: when will we get out tomorrow?
a: how about 7 o'clock?
c: that's ok.
重点讲解：
defense n. 防御
precious adj. 珍贵的
相关词汇：
infrequent; precious; rare; valuable; dear
例如:
an infrequent visitor 一位稀客
precious words 珍贵的话
rare animals 奇异的动物;rare birds 珍禽
valuable perfume 高贵的香料
dear how pure, how dear their dwelling-place. 指明它的来处纯洁而珍贵。
relic n. 估计
historical adj. 历史的
小贴士：我们跟外国人介绍景点时，需要加一句类似“the weather is wonderful.”之类的话，另外，还要赞美一下所去景点的美丽或历史。