放射源防护容器关闭后，放射源就不再放射射线，可以延长放射源的使用寿命。
参考答案：错
Ten years ago the population of our village was ______ that of theirs.
A．as twice large as
B．twice as large as
C．twice as much as
D．as twice much as
下图是“殷墟宫殿复原图”。商朝时最早把都城迁到此处的人是
A．汤
B．盘庚
C．纣
D．桀
