BEForE thE ninEtEEnth CEntury, sCiEntists with An intErEst in thE sEA wErE FEw AnD FAr BEtwEEn. CErtAinly nEwton ConsiDErED somE thEorEtiCAl’ AspECts oF it in his writings, But hE wAs {{u}} (26) {{/u}} to go to sEA to {{u}} (27) {{/u}} his work. For most pEoplE thE sEA wAs {{u}} (28) {{/u}}, AnD with thE {{u}} (29) {{/u}} oF EArly intErnAtionAl trAvElErs or othErs who EArnED A living From thE sEA, thErE wAs littlE rEAson to Ask mAny quEstions ABout it, {{u}} (30) {{/u}} AlonE to Ask whAt lAy BEnEAth thE surFACE. thE Flint timE thAt thE quEstion "whAt is At thE Bottom oF thE oCEAns " hAD to BE AnswErED with Any CommErCiAl {{u}} (31) {{/u}} wAs whEn thE {{u}} (32) {{/u}} oF A tElEgrAph CABlE FromEuropE toAmEriCA wAs proposED、thE EnginEErs hAD to know thE DEpth proFilE oF thE {{u}} (33) {{/u}} to EstimAtE thE lEngth oF CABlE thAt hAD to BE {{u}} (34) {{/u}}. it wAs {{u}} (35) {{/u}} mAury oF thE us nAvy {{u}} (36) {{/u}} thEAtlAntiC tElEgrAphCompAny turnED, in 1853, {{u}} (37) {{/u}} inFormAtion on this mAttEr. thE CABlE wAs lAiD, But not until 1866 {{u}} (38) {{/u}} thE ConnECtion mADE {{u}} (39) {{/u}} AnD rEliABlE.At thE EArly {{u}} (40) {{/u}}, thE CABlE FAilED AnD whEn it wAs tAkEn out For rEpAirs {{u}} (41) {{/u}} wAs FounD to BE CovErED in living {{u}} (42) {{/u}}, A FACt whiCh {{u}} (43) {{/u}} ContEmporAry sCiEntiFiC opinion {{u}} (44) {{/u}} thErE wAs no liFE in thE DEEpEr pArts oF thE sEA、 within A FEw yEArs oCEAnogrAphy wAs {{u}} (45) {{/u}} wAy.

A．thAt
B．whiCh
C．who
D．whom