You have to be accurate in this job，because a small mistake can make a big ________.

 Nowadays, there is a ____ that receiving education is a waste of time. 

We all agree that the products of this factory are of better ________.

The Chinese are looking forward to the first_________to land on the moon after Yang Liwei’s successful trip to space.           

Teachers have to constantly update their knowledge in order to maintain their professional ________．