I

см. тж. а не ~; в противоположность этому

• The propulsion engines for aeroplanes must operate continuously during the flight. In contrast (or By contrast), space vehicles coast freely during practically all of their useful lives.

• Such methods are difficult as well as tedious and require large amounts of starting material. Chromatography, on the other hand, is simple, rapid, and ...

• Quite the reverse.

II

см. тж. бывает и ~; в противоположность этому; и ~

• For many professionals, it was love of high country which attracted them to geology, rather than the other way (a)round (or about).

• Conversely, efficiency increases as the cut-off ratio decreases.

• To the contrary, both polynucleotides reacted more strongly with ...

• The abdominal ganglia, on the contrary, vary greatly.