We compute the low dimensional cohomologies H~q(gcN,C),
H^q(gc_N,\C) of the infinite rank general Lie conformal algebras gcN with
trivial coefficients for q≤3,N=1 or q≤2,N≥2. We also prove that the
cohomology of gcN with coefficients in its natural module is trivial, i.e.,
H^*(gc_N,\C[\ptl]^N)=0; thus partially solve an open problem of
Bakalov-Kac-Voronov in [{\it Comm. Math. Phys.,} {\bf200} (1999), 561-598].Comment: 18 page