A professor told dirty jokes in class and the women wanted to protest it. So they decided that in the next time that the professor will start with these kind of jokes they all will leave the class as a protest.

有位教授上課愛講黃色笑話，女學生想抗議。她們決定，下次教授開始說有顏色的笑話，就全部走出教室表示抗議。 

Somehow the professor heard about the plan.

不過，消息走漏到教授那裡。 

In the next lecture, in the beginning of the lecture, he said: "In Sweden a prostitute makes $2000 per night."

教授在接下來的那堂課，一開始就說：「瑞典的特種行業女郎一晚賺2000美元。」 

All the women stood up and started to leave the class. So he shouted after them: "Where are you going? The plane to Sweden doesn't take off until the day after tomorrow."

所有女生站起來，陸續走出教室。教授在後面喊：「你們要去哪裡？後天才有班機到瑞典。」