21. She wants to be a _________ (science) when she grows up.
22. There is a tall _________ (build) in front of the post office.
23. I can do my homework by _________ (I).
24. Today is Sunday. Let's go ________ (skate).
25. Please buy some _________ (toothbrush) for them.
21. scientist 22. building 23. myself 24. skating 25. toothbrushes