The purpost of this meeting is to tell us hou to keep a pet.为什么这里系动词后面接的是to do?

The purpost of this meeting is to tell us hou to keep a pet.为什么这里系动词后面接的是to do? the helm of this as the salt of this In this part of the the history of this skill This is the circle of This is the b___ of the game This is the beginning of the garden this is the ()(begin) of the term. this is the name of the product this brings out the beauty of the This was the beginning of the idea of the weekend. the frequency of the calibration of this intensity Only mark the passing of this thing What is the length of this ruler? Im on the top of this what the name of this girl On the _ (twenty) of this month.