The principalastronomical problem involved was the discrepancy between the solar year and the lunar year.
最主要的天文学难题是阳历年与阴历年之间的差异。

The Weapons to Plowshares project, or Palas por Pistolas en Espanol, worked to gather over 1, 500 firearms from the local public.
武器变铁锨运动从公众收集了约1500枝枪支。