As they moved, they left behind faint after-images and the trees 20 flickered with them like Christmas 21 ornaments.
它们移动的时候，身后留下模糊的余像，那棵树就像圣诞节的装饰一样随着它们一同摇曳。
2
After this, many researchers switched to autoganzfeld tests—an automated variant of the technique which used computers to perform many of the key tasks such as the random selection of images.