—Would you like to go out for a walk with us?— ,but I must finish my homework first.
_________ boys are there in our class?
There _____ a pen, two pencils on the desk.
—Lily, here are your pens. Please _____. —OK, Mom.
I don’t like physics ______ it’s too difficult for me.
—_____ do you _____ the book? —It’s very interesting.