维护规程规定：熔断器应有备用，不应使用额定电流不明或不符合规定的熔断器。直流熔断器的额定电流值应不大于最大负载电流的（）倍。各专业机房熔断器的额定电流值应不大于最大负载电流的（）倍。交流熔断器的额定电流值：照明回路按实际负荷配置，其他回路不大于最大负荷电流的（）倍。

A．2，2，2

B．1．5，2，2

C．2，1．5，2

D．2，2，1．5

What changes are NOT happening now that the shelf has broken up
a. It is causing changes in currents and species in the area.
b. The most southern part of the Larsen ice shelf has broken up too.
c. There will be an effect on sea level that will be felt around the world.
d. The glaciers are pushing ice in the form of icebergs into the sea.