参加讲座 attend a lecture
参军join the army
加入我们为希望工程捐赠活动join us in donating to Project Hope
计划学习文学mean to learn literature
意味着永远失去这个机会 mean losing this chance forever
听起来是个疯狂的主意sound like a crazy idea
听起来是不可能的sound impossible
习惯对儿子严格要求be used to being hard on his son