  We present low-resolution VLT spectroscopy of the afterglow of the gamma-ray
bursts (GRBs) 991216, 011211 and 021211. Our spectrum of GRB991216 is the only
optical spectrum for this afterglow. It shows two probable absorption systems
at z=0.80 and z=1.02, where the highest redshift most likely reflects the
distance to the host galaxy. A third system may be detected at z=0.77. HST
imaging of the field, obtained 4 months after the burst, has resulted in the
detection of two amorphous regions of emission, one at the projected afterglow
position, and the other 0.6" away. The spectrum shows a depression in flux in
between 4000 A and 5500 A. This could be the result of a 2175 A-type extinction
feature in the host of GRB991216, but at a rather red wavelength of 2360 A. If
this interpretation is correct, it is the first time the extinction feature is
seen in a GRB afterglow spectrum. It is centered at a wavelength similar to
that of the ultra-violet (UV) bumps inferred from observations of a few
UV-strong, hydrogen-poor stars in the Galaxy. All significant absorption lines
(except for one) detected in the spectrum of GRB011211 are identified with
lines originating in a single absorption system at z=2.142+/-0.002, the
redshift of the GRB011211 host galaxy. We also detect the Lyman alpha
absorption line in the host, to which we fit a neutral hydrogen column density
of log N(HI)=20.4+/-0.2, which indicates that it is a damped Lyman alpha
system. Using a curve-of-growth analysis, we estimate the Si, Fe and Al
metallicity at the GRB011211 redshift. For GRB021211, we detect a single
emission line in a spectrum obtained tens of days after the burst, which we
identify as [OII] 3727 at z=1.006. The corresponding unobscured [OII]
star-formation rate is 1.4 Msun/yr.
