________（甚至）a child can understand this book.

Railways are made of two“________（铁轨）”.

An English engineer drove the first ________ ________（蒸汽机火车）on a road.

One of them had a way to ________ steam engines and wheels ________（把……连在一起）.

In the 1700s, many scientists were ________ ________（从事于）the steam engine.

This is his.It ________（建于）last year.