用方框中所给词的适当形式填空，使短文完整、通顺。

Like many kids, Alan is a fan of science. But this 14-year-old eighth-grader used his science skills others. He created three prosthetic (假体的) using a 3D printer during his after-school program. He designed the hand for practice. The second one was designed for a 6-year-old boy, and the third was made for a disabled teacher at his school. Combining his love of science and his willingness to help others, Alan plans to make one hand before the year ends. He wants to do something good and helps more people.