A:温度较低,大量聚集在房间下方
B:密度较大,大量聚集在房间下方
C:温度较高,大量聚集在房间上方
D:密度较小,大量聚集在房间上方
(____)1. Let me clean the window.
(____)2. Look! The bird is on the light.
(____)3. There isa picture on the wall.
(____)4. The book is near the computer.
(____)5. The bag is on the chair.
A. B. C.
D. E.
每个细胞的生命历程虽然短暂,但对个体的生命有着重要的意义.
若四边形的两条对角线分别平分两组对角,则该四边形一定是( )