This book is worth _____.
The little girl couldn’t work the problem out. She wasn’t _____clever.
A computer cannot remember who_____; it simply does what _________.
The famous scientist was going out _____ he found himself surrounded by lots of young people.
– Look! What are those boys doing ______ the table? ---Well, they are playing cards.
We were very busy yesterday. Otherwise we _____part in the discussion.