CHD

例句：

1. 1.The center of the city is bustling with activity.
   市中心熙熙攘攘。
2. 2. The core of the problem lies in this issue.
   问题的核心在于这个问题。
3. 3. The central government has made a decision on the matter.
   中央政府已经就此事做出了决定。