Bed material samplers, as first developed , may be divided into three types.最初的河床质取样器有三种类型.In this paper the performance of two kinds of samplers sintered metal filter is evaluated.本文介绍温、湿度变化对两种改进型被动式活性炭累积氡采样器吸附性能的影响....
他们在大学偶遇，最后结了婚。They had met by chance at university and finished up getting married.他们再次偶遇的可能性非常小。It was highly unlikely that their paths would cross again.几年来，尤尔和柯克偶遇了很多次。Over the years, Yul and Kirk had crossed paths ma...