①某公司生产该商品的劳动生产率提高了50%，若其他条件不变，则2017年该商品的价格为150元。

②纸币的发行量增加了一倍，若其他条件不变，则2017年该商品的价格为150元。

③若其他条件不变，则2017年该商品的价值总量减少一半。

④该国货币贬值20%，若其他条件不变，则2017年该商品的价格为187．5元。

从所给的四个选项中选出最佳答案，将其序号填入题前括号内。

    A young man 1 himself in Japan with only enough money to buy the ticket for his 2 back home. As he knew that it would take him only two days to 3 home, he decided that he could easily spend the time 4food. So he bought a ticket and 5 the ship. The man 6his ears to the sound of the lunch bell. When dinner 7 came, he didn't go to the dining room, 8 that he was not feeling well. The next morning he still didn't have breakfast and at lunch time he again 9 in his room. But at dinner time he was so hungry that he went to the dining room and 10 everything the waiter put in front of him. “Bring me the bill,” he said. “The bill, sir?” said the waiter in surprise. “There isn't any bill. On our ship meals are included in the money for the ticket.”

下列属于遗传病的是 （   ）。