Mark the statement if it correctly describes challenges faced in building canals.
a.
geographical and topographical challenges make canal building difficult.
b.
workers sometimes die building canals, but not often.
c.
weather-related problems, such as long periods of rain, can slow down the work.
d.
canals are time-consuming and expensive to build.

The correct option are A, C and D

Explanation:

A.  Geographical and topographical challenges make canal building difficult.  True

Geographical and topographical conditions are very vital in canal building, on less steeper plain, canals can be build easily as compared to those lands where slopes are much more steeper hence canal building becomes difficult in such scenarios.

C.  Weather-related problems, such as long periods of rain, can slow down the work.  True

There is a danger of flooding during long periods of rain and also the working conditions become difficult for labors therefore, the process of canal building may slow down  the progress of canal building.

D.  Canals are time-consuming and expensive to build. True

Canal building is a difficult and time consuming task which requires usage of specialized machinery as well as trained personal who are skilled in canal building. The various costs involved in canal building includes the cost of digging, cost of labor, cost of machinery etc. Therefore, canal building is expensive as well as time consuming procedure.

yup! you are correct it is b.