第七篇
Daltonwonderedwhytheheavierandlightergasesintheatmospheredidnotseparateasoilandwaterdo.Hefinallyconcludedthattheconstituent 1 mustexistintheformof 2 particlesoratomsandthatthese 3 becompletelymixedtogetherinthe 4 .Thisthrewanewlightin 5 lawsofdefiniteproportions.Itwas 6 necessarytosupposethattheatoms 7 combinesintossmallgroupsofuniform 8 andsoformmorecomplexsubstance; 9 themysteryofthislawwas 10 .Daltonsuggested, forexample, thatcarbonmonoxide 11 formedbytheonewithone 12 ofatomsofcarbonandoxygen, 13 carbondioxideresultsfromasingle 14 ofcarbonunitingwithtwoatoms 15 oxygen.Assumingthistobetrue, 16 thedefiniteproportionsofProutslaw (17 allchemicalcompoundsthedifferentconstituents 18 enterinunvaryingproportions) wouldnaturally 19 therelativeweightsofthemany 20 kindsofatoms.
1.A.gasesB.piecesC.thingsD.gas
2.A.timelyB.trimmedC.tinyD.topical
3.A.oughtB.couldC.willD.must
4.A.skyB.atmosphereC.oxygenD.environment
5.A.variousB.manyC.theD.those
6.A.onlyB.tooC.thatD.extremely
7.A.shouldB.wereC.getD.could
8.A.constructB.structureC.pieceD.feature
9.A.butB.alsoC.thusD.nevertheless
10.A.solvedB.discoveredC.brokedD.told