KPDS 1999-2 Soru=98

It is pointed out in the passage that during the 1920s and 1930s ____ .

For many years after Mt. Everest had been shown to be
the highest mountain in the world, political conditions in
Nepal, lying south of the summit, and in Tibet to the North,
prevented mountaineers from attending an ascent. At last
in 1921 the Tibetan authorities gave permission and the
first expedition organised, as were all subsequent
expeditions by international joint committee, was sent out.
This was primarily a reconnaissance. Besides mapping
the Northern flank, it found a practicable route up to the
mountain. By 1939, six further expeditions had climbed on
the northern face. Some were hampered by bad weather,
others by problems previously little known, such as the
effect of high altitudes on the human body and spirit.
Nevertheless, notable climbs were accomplished, though
the summit was never reached.