Choose all the statements that correctly describes the 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.

Explain the cause for movement river valley civilization to early industrial centers

Which numberline shows the solution to n -3

[ou.01]which of these is the most likely use of an electromagnetic wave which has wavelength shorter than microwaves but longer than visible light? o heat food safely o neat food safely o take images of bones and teeth o transmit radio and cellular phone signals o take images of bones and teeth o transmit radio and cellular phone signals o detect the location of objects which emit heat