ensure/ɪn'∫ʊər $ -'∫ʊr/

v. make certain that sth will happen

v. [T] 保证，担保：The school took steps to ensure the safety of the students. 学校采取措施确保学生的安全。

◇[ensure (that) ...] He ensures that all complaints are treated fairly. 他保证公平对待所有投诉。

构词en- + sure