To know ________ the mountain top looks like, you need to reach it.
what
when
where
which
If we ______ day before yesterday, we would have done the job.
You _____ me because I didn't say that.
Only by practising a few hours every day ________ be able to play the piano well.
Anyone can get into the club, _______ he is a member there.
If the building project_______ by the end of this month is delayed, the construction company will be fined.