现代电动汽车的发展与上世纪初内燃机的普及有许多相似之处。

The development of electric cars today has many ___parallels with the spread of combustion engines in the early 20th century.

铁路轨道必须保持平行以确保列车安全行驶。

The railway tracks must remain ___parallel to ensure the train runs safely.

他的经历在很多方面与我的相似。

His experience ___parallels mine in many ways.