But it is always hard to pin down.(但這始終是難以確切說明。)

For something so influential and intuitively appealing, it turns out that the Hawthorne effect is remarkably hard to pin down.(作為一個如此具有影響力以及從直覺上引人入勝的理論，“Hawthorne”效應卻顯得異常難以證實。)

If they can pin down the relationship between age and rotation, a star's age will be much easier to measure.(如果他們能夠確定星星年齡與轉速之間的關系，星星的年齡測起來就簡單的多了。)

It has taken until now to pin down its exact location.(一直到現在才確定了它的準確位置。)

Some expect Apple and Microsoft to Sue Google. Yet this is unlikely, because the online giant will be hard to pin down.(有些人期待蘋果和微軟起訴谷歌，然而這是不太可能的事情，因為谷歌這個網絡巨人是很難被扳倒的。)

The cause of the disease is difficult to pin down precisely.(病因目前還難以解釋清楚。)

A trader's intent is hard to pin down, however.(然而，交易商的意向是很難被抑制的。)

Other causes are harder to pin down.(其它原因就很難下定論了。)

I almost knocked the bowling pin down.(我幾乎要把這堆保齡球瓶打倒了。)

All carbon footprints are hard or impossible to pin down accurately, but the Internet is a particularly complex case.(所有的碳足跡都很難或者不太可能精確地算出來，對于互聯網，情況更是復雜。)