The versatility of modern cross-country skiing equipment allows skiers ……… technique to diverse terrain.
……… their differences, the three models resemble ……… in a crucial respect.
Medical research at the cellular level, ……… research on the immune system, has been made possible through twentieth-century advances in techniques of genetic research.
Thirty-eight national sites are known as parks, another eighty-two as monuments, and ………
Transplanting organs ……… has proved easier than transplanting muscles.
……… is rooted in experiments in iron and steel conducted in the nineteenth century.
Intended to display the work of twentieth-century artists, ……… in 1929.
How ….. to the station from here?
……… depends on the density of both the object and the water.
The more advanced the specialization in production and the more complex the economy, ........ to make any given good reach its ultimate user by using barter.
