自去年美国疫情沦陷，我们已经一年多没旅游了。这次趁着打完疫苗，约上朋友一道，计划来芝加哥玩。

出发之前，我们最早定了个城市南部的airbnb。一个芝加哥的朋友说，那个地方可不安全哟，去之前最好准备好救命钱、防狼喷雾，和安全套。由于我们实在想把安全套的钱省下来，最后我们取消了airbnb，在另......

Communication is an important skill. A vital type is to talk with strangers. When I interned in the industry, I need let the customers get clear about......

All Ph.D. students are natural learners: they learn new methods, techniques, or even language to push their research. However, most of them naturally......