爆破施工人员必须持证上岗，人员应经过哪一级的安全培训（）
A.施工单位
B.建设管理单位
C.县以上的公安部门
参考答案：C
阅读小天地。根据短文内容判断下列句子的正(√)误(×)。
December 25th is Christmas Day. It is an important (重要的) holiday in the West. During (在……期间)
Christmas Day, people don't work, children don't go to school. Most families get together and have a big dinner.
They give and receive gifts and visit friends. The Christmas tree is an important part of Christmas. Most families
buy a tree. They also buy many things to put up the tree.
( ) 1. November 25th is Christmas Day.
( ) 2. Christmas is an important holiday in China.
( ) 3. In the west, people don't work, children don't go to school on Christmas day.
( ) 4. In the west, most families get together and have a big dinner on Christmas day.
( ) 5. The Christmas tree is an important part of Christmas.
