— Because they are busy ________ a patient.
— Be more careful.
Lance almost ran home after school. His older brother Nathan had promised to take (he) to the new skate park today. Lance was so excited he got everything ready when Nathan got home. "Who's that？" Nathan (ask), pointing out the window. Lance looked out and found his friend Haley waiting (quiet) in front of the mailbox. "What is she doing here？" Lance thought a while and remembered that he promised Haley to work on their science project today, before Nathan's promise. Skating with Nathan was certainly a (good) offer than working on the project. He could learn some new (skill) with the help of Nathan. It would be exciting experience. But if he canceled on Haley, he could imagine how disappointed she would be. Lance decided to work on the project Haley and told Nathan everything. "Good for you，"his brother said. "And ask Haley if she wants (go) to the skate park after you two finish the project." Lance couldn't believe his ears, "Really? You'd take us？""Of course, I promised，" Nathan nodded. "And a promise is a promise."
