第23题: [单项选择]The aim of voyages Maury encouraged in the 1840s was ______. A. to make some sound experiments in the oceans B. to collect samples of sea plants and animals C. to estimate the length of cable that was to be made D. to measure the depths of two oceans 参考答案:D 答案解析:解析:参见第四段第二句话。