根据句子意思，用括号中所给单词的适当形式填空，并将答案填写在答题卡标号为46~50的相应位置上。
There was a big fire in Mrs. Li’s house.       (luck) she was saved by a young fireman.
China and Russia will work together to make a contribution to a       (last) world peace.
The April 25 disaster in Nepal is       (report) to have taken the lives of more than 8,000 people, with more than 16,000 injured.
My father and Uncle Wang are close friends. Their       (friend) goes back to when they were at school together.
Students, carrying their mothers on their backs, took part in a fun race       (celebrate) Mother’s Day at a middle school in Hefei, on May 7.