why download fail?

[pikeyang]

python tools/audioset2.py lists/audioset1.csv ../pfann_dataset/audioset python tools/audioset2.py lists/audioset2.csv ../pfann_dataset/audioset python tools/audioset2.py lists/audioset3.csv ../pfann_dataset/audioset

download -4N3GjgnIQ0 from 260 to 270

failed to download ;-( stop for a moment~~~ download -5lI0Wt-pNE from 250 to 260 failed to download ;-( stop for a moment~~~ download -ADTZNx531s from 340 to 350 failed to download ;-( stop for a moment~~~ download -D1uGn8bvIA from 40 to 50 failed to download ;-( stop for a moment~~~ download -DZN4RxMD3s from 140 to 150 failed to download ;-( stop for a moment~~~ download -DrChjJRNIk from 80 to 90 failed to download ;-( stop for a moment~~~ download -EveIKsp3nE from 270 to 280