摘要：
This thesis suggests that the single reference is relative, whereas the reference system is absolute. The ＂dixia＂ which means ＂on the ground＂ can not be explained by single reference. The reference system of ＂dixia＂ consists of direction reference and location reference. Although the reference system of ＂dixia＂ concerns with people （not limits to speakers）, ＂di （地）＂ can still function as a reference, since it is the object in background, the substance which used to determine the location, which is the same as the ＂di＂ in ＂ ~shang （地上）＂. ＂dixia＂ can be used independently and contrastively. Only when used independently, it requires the height of goal can be overlooked. This is the result of the restriction of reference system of ＂dixia＂. In this restriction of reference system, the use of ＂dixia＂ has a ＂low-position effect＂, which means the goal by ＂dixia＂ is always on a comparatively low position. bearing
摘要：
Diachronically, there are some changes in the object of the verb chi（吃）. Firstly, we can find the changes in the semantic type of the object. In the past there were mainly patient-objects, but later, there were more and more nonpatient-objects. Secondly, we can find some changes in the denotation of the object from nouns denoting food to non-food. Besides, the nouns denoting food also have undergone some changes from ＂solid food → solid and non- solid food →solid food mainly＂ .
