The teacher often w____ to or calls the student‘s parents.

问题描述:

The teacher often w____ to or calls the student‘s parents.

这里应该是和call并列的,因为call是打电话,所以前面应该是一种联系方式。
可知用w开头的一,应该是“写信”最合适,所以填write。
write to是“写信”的意思。

writes