On a sunny day, a yellow school bus heads to Elver Park in Madison, Wisc. The seventh graders inside are excited to_________ the rockets they've built in class.

At the park, the students find their assigned flag posts, armed with their rocket, notebook, pencil and angle finder（量角器）. Two at a time, they march to the platform and_________their rocket for take-off. They wait for their teacher's_________to start the countdown: 5, 4, 3, 2, 1…Go!

With the angle finder and a little math, they estimate each rocket's maximum_________. They calculate how their rocket_________against 90 others made by their classmates and teacher.

"With the rocket unit, I teach the_________principles of physics and motion（移动）," explains David Ropa. He teaches science at Spring Harbor Middle School and advocates learning by_________. That includes taking math and science into the park.

"Kids, like all humans, are doing science all the time," says Ropa. "They_________the world through play," he_________, "whether it's stacking toys or building bike ramps." They have a hypothesis（假说）. They set up a test. They____________the results. Then they adjust their____________.

"The____________his students use at school," says Ropa, "are similar to those that many adults use at work." Some of these adults____________a white lab coat and carry a business card with the word scientist". Most don't.

In Madison' s Elver Park, the students make their____________fly as high as they can. That teaches them the physics of____________. "It also develops a sense of creating____________and hopefulness," says Ropa.

Some kids will never____________that rocket launch. For others, the "calculation" may hook them on____________.

"Kids are____________," says Ropa. "Just watch them when the sea____________a dead fish. That's what scientists really are-very curious people who keep that curiosity going in their jobs."