System_gylchredol
Tymheredd
Y_Môr_Coch
Nofio
Metabolaeth
Llanw
Gorbryder
Grym
Anadlu
System_resbiradu
Gwasgedd
Lipid
Barriff_Mawr
Robert_Boyle
Tyndra’r_cyhyrau
Hydoddedd
David_Attenborough
Chwarel_Dinorwig
Leni_Riefenstahl
Resbiradu
Riff
Cymorth_cyntaf
Salwch_symud
Tim_Peake
Lusitania_(llong)
Pwysau_(grym)
Hypothermia
Y_Gwasanaeth_Awyr_Arbennig
Royal_Charter
Fertigo
Dafydd_Williams
Loch_Long
John_Smeaton
Triniaeth_ocsigen
Whyalla
Wast_Water
Le_Monde_du_silence
Drifft_y_glannau
Plymio_sgwba
Kirsty_MacColl
David_Bellamy
Le_Monde_sans_soleil
Porth_Dafarch
Margaret_Rule
Mehgan_Heaney-Grier
Emma_Hwang
Martin's_Haven