关键用句：
a solar eclipse occurs when the moon passes between the sun and the earth so that the sun is fully or partially covered.
日蚀发生在在月球处于太阳和地球之间时,这导致太阳被完全或部分地遮住了
a solar eclipse occurs when the moon passes between the sun and the earth so that the sun is fully or partially covered. this can only happen during a new moon, when the sun and moon are in conjunction as seen from the earth. at least two and up to five solar eclipses can occur each year on earth, with between zero and two of them being total eclipses. total solar eclipses are nevertheless rare at any location because during each eclipse totality exists only along a narrow corridor in the relatively tiny area of the moon's umbra.
a total solar eclipse is a spectacular natural phenomenon and many people travel to remote locations to observe one. the 1999 total eclipse in europe helped to increase public awareness of the phenomenon, as illustrated by the number of journ