A successful scientist needs _____ if he wants to make hypothesis (假设) of how processes work and how events take place.

Her question was so difficult that I could hardly make any ____ of it at all.　 

Mo Yan’s winning the 2012 Nobel Prize for Literature shows the world’s _______ of contemporary Chinese Literature.

By all _______, you must try every _______ to help him.

Put the_______of your tongueagainst your upper teeth when you produce the sound。