- 01.Breathingandrespiration
- 0:0 免费01.Breathing,respirationandgase ...
- 0:0 免费02.Thehumangasexchangesystemand ...
- 0:0 免费03.Estimatinglungvolume
- 0:0 免费04.Adaptationsofthehumanlungsfo ...
- 0:0 免费05.Cellularrespiration
- 0:0 免费05.Cellularrespiration_1
- 0:0 免费06.Aerobiccellularrespiration
- 0:0 免费07.Anaerobiccellularrespiration ...
- 0:0 免费08.Anaerobiccellularrespiration ...
- 02.Acidsandbases
- 0:0 免费01.Acidsandbases
- 0:0 免费02.pHscaleanduniversalindicator ...
- 0:0 免费03.Practicalredcabbageindicator ...
- 0:0 免费04.Chemicalreactionsacidandmeta ...
- 0:0 免费05.Metaloxidesandnon-metaloxide ...
- 0:0 免费06.Chemicalreactionsneutralisat ...
- 0:0 免费07.Chemicalreactionsacidandmeta ...
- 03.Magnetsandelectromagnets
- 0:0 免费01.Magneticpoles
- 0:0 免费02.Themagneticfieldofabarmagnet
- 0:0 免费03.Electromagnets
- 0:0 免费04.Currentthroughanelectromagne ...
- 0:0 免费05.Usingelectromagets
- 04.Plantnutritionandphotosynthesis
- 0:0 免费01.Plantnutrition
- 0:0 免费02.Photosynthesis
- 0:0 免费03.Adaptationsofplantsforphotos ...
- 0:0 免费04.Adaptationsofplantsforphotos ...
- 05.Materials
- 0:0 免费01.Materialsandcompositesinclud ...
- 0:0 免费02.Structureofpolymers
- 0:0 免费03.Thereactivityseriesformetals
- 0:0 免费04.Chemicalreactionsdisplacemen ...
- 0:0 免费05.Catalysts
- 06.Hiddenforces
- 0:0 免费01.Gravitationalforceandweight
- 0:0 免费02.Stretchingsprings
- 0:0 免费03.Hookeslaw
- 0:0 免费04.Stretchingrubber
- 0:0 免费05.Theforceofafloor
- 0:0 免费06.Levers
- 0:0 免费07.Turningforces
- 0:0 免费08.Floating,massandshape
- 0:0 免费09.Pressure
- 0:0 免费10.Pressureatdifferentdepthsand ...
- 07.Adaptations,competition,naturalselectionandevolution
- 0:0 免费01.Fossilsshowthatspecieschange ...
- 0:0 免费02.Understandingtimescales
- 0:0 免费03.Adaptations
- 0:0 免费04.Competition
- 0:0 免费05.Heritablevariation
- 0:0 免费06.Naturalselection
- 0:0 免费07.Amodelofnaturalselection
- 0:0 免费08.Evolution
- 08.Carboncycleandclimatechange
- 0:0 免费01.Physicalweatheringanderosion
- 0:0 免费02.Formationofsedimentaryrock
- 0:0 免费03.Fossilsandtherockcycle
- 0:0 免费04.Formationoffossilfuels
- 0:0 免费05.Gasesintheatmosphere
- 0:0 免费06.Atmosphericcarbon
- 0:0 免费07.Thecarboncycle
- 09.Waves
- 0:0 免费01.Waterwaves
- 0:0 免费02.Soundwaves
- 0:0 免费03.Speedofsound
- 0:0 免费04.Hearingsound
- 0:0 免费05.Ultrasound
- 10.Diseaseanddrugs
- 0:0 免费01.Differencesbetweeninfectious ...
- 0:0 免费02.Thegasexchangesysteminhealth ...
- 0:0 免费03.Lifestylediseases
- 0:0 免费04.Asthma
- 0:0 免费05.Smoking
- 0:0 免费05.Smoking_1
- 0:0 免费06.Vaping
- 0:0 免费07.Recreationaldrugusedepressan ...
- 0:0 免费08.Recreationaldrugusestimulant ...
- 0:0
免费09.Solventabuse - 11.Patternsintheperiodictable
- 0:0 免费01.Groupsofelementsintheperiodi ...
- 0:0 免费02.Group1and2metals
- 0:0 免费03.Group7(halogens)
- 0:0 免费03.Group7(halogens)_1
- 0:0 免费04.Group0(NobleGases)
- 12.Resistanceandparallelcircuits
- 0:0 免费01.Electricalresistance
- 0:0 免费02.Thicknessofawire
- 0:0 免费03.Lengthofawire
- 0:0 免费04.Makingparallelcircuits
- 0:0 免费05.Voltageinparallelcircuits
- 0:0 免费06.Loopsofaparallelcircuit
- 0:0 免费07.Measuringcurrentinaparallelc ...
- 0:0 免费08.Comparingseriesandparallelci ...
- 0:0 免费09.Mainselectricity
- 13.Reproductioninplants
- 0:0 免费01.Flowerstructure
- 0:0 免费02.Pollinationandfertilisation
- 0:0 免费03.Insectsandfoodsecurity
- 0:0 免费04.Fruitandseeds
- 0:0 免费05.Factorsaffectingseedgerminat ...
- 0:0 免费06.Factorsaffectingseedgerminat ...
- 0:0 免费07.Seeddispersalpractical
- 0:0 免费08.Seeddispersaldataanalysis
- 14.Cells
- 0:0 免费01.Microscopes
- 0:0 免费02.Cellstructures
- 0:0 免费03.Specialisedanimalcells
- 0:0 免费04.Specialisedplantcells
- 0:0 免费05.Unicellularorganisms
- 0:0 免费06.Organisation
- 0:0 免费07.Diffusion
- 15.Atomsandtheperiodictable
- 0:0 免费01.Elements
- 0:0 免费02.Compounds
- 0:0 免费03.Chemicalreactions
- 0:0 免费04.Conservationofmass
- 0:0 免费05.DevelopmentofthePeriodicTabl ...
- 0:0 免费06.Metalsandnon-metals
- 0:0 免费07.Group1
- 0:0 免费08.Group7
- 16.Energy
- 0:0 免费01.Energystoresandtransfers
- 0:0 免费02.ConservationofEnergyandEffic ...
- 0:0 免费03.Conduction
- 0:0 免费04.Convection
- 0:0 免费05.Radiation
- 0:0 免费06.Insulation
- 0:0 免费07.Powerandenergy
- 0:0 免费08.Energyinthehome