a shortage of grain的用法和样例：
- There is a shortage of grain because of poor crops.
- The war was lost because of a shortage of munitions.
- There is a shortage of salt in this country.
- There was a shortage of oxygen at the top of the mountain.
- At the founding of the People's Republic,we inherited from old China a ruined economy with virtually no industry. There was a shortage of grain,inflation was acute and the economy was in chaos.