Could I invite my friends to my birthdayparty—Sorry, you ______.

I’m as busy as a bee; ________ you bother me with so many questions now

Scientists have to work hard to keep _____ with modern discoveries and developments. [ ]

I really apologize for not being able to join in your birthday party.–________. We’ll get together later.

We attend lectures in the school meeting room at weekend _______ seats more than 800 students.