例句與造句

1. Pulsating variables are stars that are continuously expanding and contracting and therefore show variations in brightness
   例如脈動變星就是恒星本身不斷膨脹收縮，造成光度亦出現(xiàn)相應(yīng)的變化。
2. Pulsating variables vary periodically , but for some stars , there may be sudden changes in their brightness . such kinds of stars are called eruptive variables . they include
   ：脈動變星的光度會周期性地改變，但有一些恒星的光度會在毫無先兆下變得光芒萬丈，這種恒星包括新星和超新星皆統(tǒng)稱為爆發(fā)變星。
3. It's difficult to find pulsating variable in a sentence. 用pulsating variable造句挺難的