what is the exposition of Alice’s Adventures in Wonderland

In the novel's exposition, Alice is sitting by the bank of a stream, bored, when she notices the White Rabbit dressed in a waistcoat scurrying along. The rabbit stops to pull a pocket watch out of its waistcoat pocket, mutters to itself that it will be late for something, then scurries off and disappears down a hole. Alice follows the rabbit down the hole, and suddenly finds herself falling, though not so fast that she is in any danger of being injured when she lands.