1 . Dogs have a very good sense of smell and are often used to search for ________(survive) in an earthquake. （所给单词适当形式填空）

2 . 这对夫妇在事故中幸存下来，但他们是仅有的两名幸存者。他们为自己的幸存感到幸运。他们主要靠丈夫的收入生活。最后，丈夫比妻子多活了10年。
The couple ________ the accident, but they were the only two _______. They felt lucky for their _______. They survived mainly _______ the husband's income. Finally, the husband survived his wife ______ 10 years.

3 . A 99-year-old s__________ of the Nanjing Massacre（大屠杀） died on Wednesday, reducing the number officially registered to 73. （根据首字母填空）

4 . Workers built shelters for ______________whose homes had been destroyed. 幸存者（根据汉语意思填空）