如图所示,一束光线射向O处的光学元件后,会聚在其主光轴上的S′点;当去掉光学元件后,光线会聚于S点。则可判断,该元件一定是A. 凸透镜 B. 凹透镜C. 凸面镜 D. 凹面镜 答案:【答案】A【解析】读图可知,当没有光学元件时,光线会聚在S点,而当有光学元件时,光线会聚在左侧的S′点,说明加上光学元件之后,光线较刚才会聚了,因此,这一光学元件应该是凸透镜。故选A。 Compared
with his sister, Jerry is even more to,
and more easily troubled by , emotional and relationship problems.
A.
sceptical B.
addicted C.
available D. sensitive