And Burke says that actually does seem to help, based on randomized studies – the researcher's gold standard. 随机研究
Steinberg and Gardner randomly assigned some participants to play alone or with two same-age peers looking on. 随机分配
A car that takes off from some London street and lands in another random street is unlikely to happen,” says Prof. Gray, a leading aeronautical engineer. 在任意一条街道上着陆
We looked at a random sample of 120 families. 我们研究了随机抽样的120个家庭。