Which answer choice includes two obstacles that those building the Panama Canal had to overcome? frequent storms; wars

extreme heat; landslides

construction of locks; lack of workers

extreme cold; dust storms

I would say construction of locks; lack of workers

Explanation:

they did have workers but about 22,000 died while the construction of that canal due to sickness also organisation and engineering were problems soo that is the closest

ww1 weapons: tank. tanks were used for the first time in the first world war at the battle of the somme. they were developed to cope with the conditions on the western front. the first tank was called 'little willie' and needed a crew of 3.