direct observation

• 直接调查

direct observation的用法和样例：

例句

1. Use methods that permit direct investigation of the question.
   使用直接调查研究问题的研究方法。
2. These direct investigations aim at addressing problems at a higher level by adopting a proactive and preventive approach.
   进行直接调查的目的，在于以积极主动的态度，从较高层次着手解决问题。
3. Most information was collected by direct observation of the animals' behaviour.
   大部份信息都是通过直接观察动物的行为收集到的。
4. Ophthalmoscopy affords the only opportunity for direct visualization of blood vessels.
   检眼镜检查法提供直接观察血管的唯一机会。