如图:B处有一船,向东航行,上午9时在灯塔A的西南58.4千米的B处,上午11时到达灯塔的正南C处,那么这船航行的速度是( )千米/时.
A.19.65 B.20.65 C.21.65 D.22.65
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如图所示,河对岸有水塔CD.今在A处测得塔顶C的仰角为30°,前进20米到达B处,又测得C的仰角为45°,则塔高CD(精确到0.1m)是( )m
0 210581 210589 210595 210599 210605 210607 210611 210617 210619 210625 210631 210635 210637 210641 210647 210649 210655 210659 210661 210665 210667 210671 210673 210675 210676 210677 210679 210680 210681 210683 210685 210689 210691 210695 210697 210701 210707 210709 210715 210719 210721 210725 210731 210737 210739 210745 210749 210751 210757 210761 210767 210775 366461
A.25.3 B.26.3 C.27.3 D.28.3
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