He set a very big iron ball and a big hammer on the stage.

他在讲台上放置了一个很大很大的铁球和一把铁锤。

youdao

If I throw up a hammer, then the center of mass and only the center of mass will just go along a perfect parabola as if it were just a tennis ball.

我若是抛铁锤，那么质量重心，也是唯一的质量重心，会沿完美抛物线运动，就像一颗网球。

youdao

He picked up a ball-peen hammer, leaned on the passenger-side fender, and tapped twice on the EGR valve.

他拿起一个榔头，在右侧挡泥板前弯下身，轻轻敲了两下废气循环阀。

youdao

His tools, notably a three-pound ball-peen hammer, clanked in a greasy leather bag suspended from the handlebars.

NEWYORKER: Nawabdin Electrician

That explains why Nickeas recently bought a bright red Hammer "Arson" bowling ball "it has some real pop, " he said.

WSJ: Mets: A Bowling Team That Dabbles in Baseball