方位介词 — 英语阅读题

Read the passage and answer the question. It is the first day of the new school term. Lily is showing her friend Tom around the classroom. Her schoolbag is on the desk. Her English book is in the schoolbag. Her pencil case is under the chair, and two new pencils are in the pencil case. Tom's football is behind the door. Lily's red cap is between the two desks near the window. "Welcome back to school!" Lily says to Tom with a smile. Question: Where is Lily's pencil case? You may answer in English or Chinese.