投球

tā men qǐng le yī gè zhí yè xuǎn shǒu tì tā men tóu qiú

他们请了一个职业选手替他们投球。

They rang in a professional player to pitch for them.

tā yī zhí gěi xué sheng men shì fàn rú hé tóu qiú

他一直给学生们示范如何投球。

He was showing the students how to pitch the ball.