1. achieve v. 取得；获得

achievement n. 成就

Cf. achieve high grades (goals) earn one’s respect (living, money) acquire skills/knowledge gain experience/support/reputation

2. average n. /adj.

平均；平均的

3. challenging adj. 有挑战性的

Cf. challenge n. 挑战；v. 挑战

meet the challenge; challenge sb. to do sth.

On average, below average, above average