• The estimated extent of the canyon ...
• These figures are speculative ( or tentative ), but they give some idea of ...
• The estimated extent of the canyon ...
• These figures are speculative ( or tentative ), but they give some idea of ...
Циммерман М., Веденеева К.. Русско-Английский научно-технический словарь переводчика. Russian-English scientific dictionary for translators. 2012