  Multiloop superstring amplitudes are calculated in the explicit form by the
solution of Ward identities. A naive generalization of Belavin-Knizhnik theorem
to the superstring is found to be incorrect since the period matrix turns out
to be depended on the spinor structure over the terms proportional to odd
moduli.
  These terms appear because fermions mix bosons under the two-dim.
supersymmetry transformations. The closed, oriented superstring turns out to be
finite, if it possesses the ten-dimensional supersymmetry, as well as the
two-dimentional one.
  This problem needs a further study.
