Mark agrees to purchase a frost-free freezer from a local retail outlet. He signs the purchase order and effects payment. However, when the freezer is delivered he soon discovers that the freezer is not frost-free.Required:Explain what action may be brought forward by Mark on the basis of invalidity of a contract. (10 marks)

SVR(体循环阻力)()
CO(心排血量)()
CI(心脏指数)()
EF(射血分数)()
PVR(肺血管阻力)()

A．=每搏输出量(SV)/左心室舒张末期容积(LEDV)

B．=60×(MAP-CVP)/CO

C．=每搏输出量(SV)×心率(HR)

D．=CO/体表面积(BSA)

E．=60×(PAP-LAP)/CO