Answer:
The invention of the steam engine and the construction of steel bridges to carry trains across various physical features led to ever-increasing demand for the materials and labor to build more trains and tracks
Explanation:
Chapter 11 AP HUG quiz. Thank me later.
Answer:
After World War 2, The late 40s to mid 50s saw a huge rise in baby population also known as baby boomers
Answer:
20% of number 1 to 70 has one or nine in it
Explanation:
20% numbers from 1 to 70 have 1 or 9 in the unit's digit. 1,9,11,19,21,29,31,39,41,49,51,59,61,69 this is that series of numbers .These are total 14 numbers out of 70 so 14/70×100 gives us 20 % occurrence of 1 or 9 at unit place.