当发生手足搐搦症时，说明其血钙为（）

A.1.25～1.38mmol／L

B.1.5～1.63mmol／L

C.<1.75mmol／L

D.<2.0mmol／L

E.<2.13mmol／L

Mr Smith has_______ cancer for two years but he is still working very hard.

A．suffered

B．suffered from

C．suffered by

D．suffering from