Don’t eat too much candy. It _____ your teeth.

在下面一段文字横线处填入语句，衔接最恰当的一项是我们只有知道一个国家人民生活的乐趣，才会真正了解这个国家， 。 。 ， ，我们才会看到一个内在的人，看到他真正的自我。①只有当一个人开始做他所喜欢做的事情时，他的个性才会显露出来②正如我们只有知道一个人怎样利用闲暇时光，才会真正了解这个人一样③精神可以随心所欲地游荡之时④只有当社会与公务的压力消失，金钱、名誉和野心的刺激离去

He had just sent an e­mail to his pal on the Internet ________ the system broke down

She has __________ close friends so that she really doesn’t know __________

He has ordered a watch on line for his father and it _______ to him before Father’s Day.