Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
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Question: In geology, a supercontinent is a landmass comprising more than one continental core, or craton.

Answer: n geology, a supercontinent is land with more than one continental core, or craton.

Question: Normally a pawn moves by advancing a single square, but the first time each pawn is moved from its initial position, it has the option to advance two squares.

Answer: Normally a pawn moves by advancing a single square. The first time each pawn is moved from its initial position, it has the option to advance two squares.

Question: From 1948 - 52, a series of guest conductors led the orchestra, including Leonard Bernstein and Leopold Stokowski.

Answer:
From 1948 - 52 a series of guest conductors led the orchestra.