In fact, her persistance(坚持) is one of the ____ why Tu Youyou won the Nobel Prize.

There is no doubt, in my opinion,_______ matters is not the speed, but the quality of the product.

If Icould help___,I needn’t have taken trouble to send the broken computer to therepairing centre.

We must learn how these “problems” “challenges”.

Let me _____it _____ you, sir!— Sure, go ahead.