"when making contingency estimates, the contractor should"

The contractor should take into account the time of year, the estimated completion time for the project, the typical weather of the region, and potential for shortages in supply. The time of the year determines the typical weather. Hot weather can slow down the project. Extreme cold or rainy weather would do the same.

Answer countries with high purchasing power today may not continue to show the same growth in the future;

Answer(a) stop payment on the first check; then write a second one;