underline
/ˌʌndəˈlaɪn; ˌʌndɚ`laɪn/ (also underscore) v [Tn]
1 draw a line under (a word, etc) 在（词等）下面画线.
2 (fig 比喻) reinforce (an attitude, a situation, etc); emphasize 强化（态度、 形势等）; 加强; 强调
Strikes by prison officers underline the need for reform in our gaols. 监狱工作人员罢工一事, 突出地表明我们的监狱制度亟须改革.