Use methods that permit direct investigation of the question. 使用直接調查研究問(wèn)題的研究方法。
These direct investigations aim at addressing problems at a higher level by adopting a proactive and preventive approach. 進(jìn)行直接調查的目的，在于以積極主動(dòng)的態(tài)度，從較高層次著(zhù)手解決問(wèn)題。
Most information was collected by direct observation of the animals' behaviour. 大部份信息都是通過(guò)直接觀(guān)察動(dòng)物的行為收集到的。
Ophthalmoscopy affords the only opportunity for direct visualization of blood vessels. 檢眼鏡檢查法提供直接觀(guān)察血管的唯一機會(huì )。
