狄考文将他的工作兼化验室每年一次做公开展览，届时必在会场上做讲述。

Once a year there would be a day for showing his workshop to the public;

youdao

狄考文将他的工作兼化验室每年一次做公开展览，届时必在会场上做讲述。

Once a year there would be a day for showing his workshop to the public;

youdao