They cap the igloo by dropping a keystone, or block with edges cut wider above than below, into the remaining gap in the roof, and "grout" the gaps between blocks of snow with additional snow.

人们用拱顶石来盖顶，或者把雪块削切得上边缘比下边缘更宽，放进剩下的屋顶缺口里，再用雪来塞满雪块间的缝隙。

youdao

The payroll tax cut is tied into a study on the Canadian Keystone Pipeline transaction, another complication to the argument.

FORBES: Is a 2 Month Tax Cut a Cut?