Britain's industrial heritage is probably richer than that of any other nation, for it was here during the course of the 18th and early 19th centuries that occurred the series of major technological advances which heralded the greatest social and economic upheaval in the history of mankind — the upheaval which became known as the Industrial Revolution.

请教老师，本句是否含有强调句型？其次，最后一句红体字是什么成份，是补充说明吗？望老师能句式分析。谢谢老师。