---Do you think Peter is free today?---I don’t think so. Recently he has been ______ the most of his time to prepare for the final examinations.
I believe the teacher's explanation will ________this puzzling problem.
The famous artist said that his success was ________his hard work and perseverance.
________the latest estimates,insects account for probably 4 to 6 million of the species of creatures living on the planet.
The cakes are delicious. He'd like to have _______third one because ________second one is rather too small.
This kind of tiger has nearly died________,so we must take some measures to save them.