I don’t know when he ____. But if he ____, I’ll ring you up.
I thought I had lost my key. But luckily, it ___________ the other day.
You are sure to fail the test _________ you spend more time doing something helpful.
--There __________ a big lake near my house. But it’s gone now.--That’s too bad.
– Why do you like the boy so much, Sophia?– Because he is trying __________ best to catch up with others this term.
Paper is made ____________ wood. So saving paper is saving forests.