例句與造句

1. The people of the Jeulmun practiced a broad spectrum economy of hunting, gathering, foraging, and small-scale cultivation of wild plants.
2. While for useful process gain the transmitted DSSS signal must occupy much wider bandwidth than simple a . m . of the original signal alone would require, its frequency spectrum can be somewhat restricted for spectrum economy by a conventional analog bandpass filter to give a roughly bell-shaped envelope centered on the carrier frequency.
3. It's difficult to find spectrum economy in a sentence. 用spectrum economy造句挺難的