[单项选择]The discovery of the Antarctic not only proved one of the most interesting of all geographical adventures, but created what might be called "the heroic age of Antarctic exploration". By their tremendous heroism, men such as Shackleton, Scott, and Amundsen caused a new continent to emerge from the shadows, and yet that heroic age, little more than a century old, is already passing. Modern science and inventions are revolutionizing the techniques of former explorers, and, although still calling for courage and feats of endurance, future journeys into these icy wastes will probably depend on motor vehicles equipped with caterpillar traction rather than on the dogs that earlier discoverers found so invaluable.
Few realize that this Antarctic continent is almost equal in size to South America, and enormous field of work awaits geographers and prospectors. The coasts of this continent remain to be accurately charted, and the mapping of the whole of interior presents formidable task to t
A. About 100 years ago.
B. In this century.
C. At the beginning of the 19th century.
D. In 1798.