Getting objects by guid in rhino python

Hi everyone!

I tried to get intersection point between a surface and a curve:

crv = rs.GetCurveObject()[0]
srf = rs.GetSurfaceObject()[0]
dom = rs.CurveDomain(crv)

print type(Rhino.Geometry.Intersect.Intersection.CurveSurface(crv, dom, srf, 0.1))

But it said "Message: expected Curve, got Guid". And I think CurveSurface function needs a Curve object not Guid of that object! How can get an object by its GUID?