1. crack a smile 展颜微笑，莞尔一笑

　　Definition: to smile, especially when you do not feel like smiling.

　　The man was willing to do anything to make his wife crack a smile. （为了让他的妻子展颜微笑，他愿意做任何事情。）

　　2. laugh a hearty¹ laugh/laugh heartily² 放声大笑，开怀大笑

　　Definition: to laugh loudly and uncontrollably

　　Upon hearing that he had won the lottery³, the man laughed heartily. （知道自己中奖了，这个男人开怀大笑。）

　　3. force a smile 强作欢颜

　　Definition: to smile even though you feel sorrowful or unhappy

　　At the funeral, he forced a smile for anyone who offered condolences. （在葬礼上，他强颜欢笑面对前来吊唁的人。）

　　4. a saccharine⁴ smile 谄笑，谄媚的笑

　　Definition: a smile designed to please others

　　When he talks to his boss, he puts on a saccharine smile. （他跟老板说话的时候，满脸都是谄媚的假笑。）

　　5. smile bitterly 苦笑

　　Definition: to smile when you have no choice or can do nothing to help

　　The student smiled bitterly when his teacher caught him copying his homework. （抄作业被老师抓到后，这个学生满脸苦笑。）