There was a big fire in the building last night. ____, all the people were able to escape.

A．Unluckily

B．Fortunately

C．To be sure

D．Above all

从大兴安岭到内蒙古草原再到新疆，降水量的变化规律是[ ]

A．逐渐增加

B．逐渐减少

C．一样多

D．没有规律