By 1900, over children worked in factories or fields.

1.7 million

Explanation:

In the early 1900s, children frequently worked in factories. Some of them started working at the age of 5. They worked for long periods of time and in the worst conditions.The North had stricter laws regulating child labor so, many factories moved to the South so they could continue employing children.

the answer is c.

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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.