interviews with a randomly selected sample of 30 girls aged between 13 and 18.

对随机抽取的30名年龄在13至18岁之间的女孩的访谈。

They were randomly allotted to one or other of two groups.

他们被随机分配到两个组中的一个。

drinks and magazines left scattered randomly around.

随意四处散落的饮料和杂志。