6. The reason___________he explained to us was not true. 7. The reason___________he didn't turn up was unknown. 8. The boy _______ is playing ping-pong is my classmate. 9. The e-mail ________I received yesterday was from my sister. 10. I hate people _______ talk much but do little.
(which/that)
why/for which
who / that
who / that
which/ that