Was it ______ he was playing volleyball on the playground_________ he got hurt?

A．that; when

B．when; that

C．that; where

D．where; that

印刷企业中无论是制版用还是车间照明光源，应当选择具有—的光源。（）

A、连续光谱

B、混合光谱

C、连续光谱或混合光谱

D、线状光谱