他号召大家一起去参加志愿活动。
tā hàozhào dàjiā yīqǐqù cānjiā zhìyuàn huódòng 。
He calls on everyone to participate in volunteer activities.
学校号召学生们关心环保问题。
xuéxiào hàozhào xuéshēng mén guānxīn huánbǎo wèntí 。
The school appeals to students to care about environmental issues.
政府号召公众积极参与国家建设。
zhèngfǔ hàozhào gōngzhòng jījí cānyù guójiā jiànshè 。
The government calls on the public to actively participate in national construction.