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

It is clear that in modern society high _______ and demands are placed on students. 

In many ways China’s rapid growth has been seen as a(n) ______ to improve the cooperation with other countries.

We look forward to the day when motorcars will be replaced by some less dangerous ____ of transport.

The government has lost a great deal of   _because of the large increase in food price.