upper half plane

例句：

1. 1. The upper half of the tableis covered with a cloth.
   桌子的上半部分被一块布覆盖着。
2. 2. Theupper half of the city is bustlingwith activity.
   城市的上半部分正忙碌地活动着。
3. 3. The upper half of thesky was filled with stars.
   天空的上半部分布满了星星。