while my sister (is) having her maths lesson.填is还是are
问题描述:
while my sister (is) having her maths lesson.填is还是are
答
当然是is ,is的主语是单三人称,are的主语是二人称及复数对象.
while my sister (is) having her maths lesson.填is还是are
当然是is ,is的主语是单三人称,are的主语是二人称及复数对象.