Larry和李华正在为他们的朋友Laura担心。他们两人都觉得Laura好像有什么心事。今天李华会学到两个常用语：clam up和to tank。
LL: Laura has been acting really strange lately, but every time I try to ask her what's bothering her, she just clams up.
LH: 我也注意到了，Laura最近是有点怪怪的。我也问过她怎么回事，她就是不肯说....对了，Larry，你刚才说clam up，那是什么意思啊？
LL: To clam up is to become silent and refuse to talk about something.
LH: To clam up就是闭紧了嘴巴，不肯把心里的事告诉别人。可是Larry，clam不是一种蛤蜊吗？这跟说不说话有什么关系？
LL: Yes, in fact, that's where the expression comes from. Clams can close their shells ver
