1. We observed the circulation of blood in frogs.
   我们观察了青蛙的血液循环。
2. You should observe the exhibition carefully.
   你应该仔细观看这个展览会。
3. He observed a man trying to force the lock.
   他看到一个人正在设法撬锁。
4. They observed how the tiny wings were fitted to the body.
   他们观看了微型翼的安装情况。
5. All these rules must be strictly observed.
   所有这些规定都必须严格遵守。

　1个形容词解释