词根词源，challenge

challenge的词根词源为chal

例句

1、

Schools must meet the challenge of new technology.

学校必须迎接新技术的挑战。

2、

The company faces major challenges over the course of the next few years.

这家公司今后几年将面临重大的挑战。

3、

It was a direct challenge to the president's authority.

这是对主席权威的直接质疑。