【单选题】有一介质薄膜,其折射率为n(n>1),其上下两侧的介质都为空气。如果一束单色光由上表面入射到介质膜上,则下列说法错误的是[ ]
A.
在介质膜上表面一侧两反射相干光产生的干涉中,两反射光之间存在半个波长的附加光程差。
B.
在介质膜上表面一侧两反射相干光产生的干涉中,两反射光之间不存在半个波长的附加光程差。
C.
在介质膜下表面一侧两透射相干光产生的干涉中,两透射光之间不存在半个波长的附加光程差。
【判断题】从性质上讲,旅游业是一个重要的经济行业,属于第三产业。( )
【单选题】连侧围手袋中,袋盖袋口中段拱位加 ( )。
【简答题】Questions 18~21 are based on the following dialogue on sports. What are the man's hobbies? [A] Running and thinking. [B] Running and jumping. [C] Running and climbing. [D] Running and skiing.
【单选题】度假、孩子上学、购买和装修住宅一般是由什么方式的家庭决策来作出决定的?( )。
【简答题】Questions 14~17 are based on the following dialogue on traveling. What is Ms. Bush's main purpose for the trip? [A] Sightseeing in Australia and the Far East. [B] Visiting a friend in Cairo. [C] Atten...
【简答题】Act out the 1st dialogue on page 21 and the 2nd dialogue on page 25 with your partner and upload the video of your performance on the platform here.
【单选题】在基底上镀制一层介质薄膜,其几何厚度为d,折射率为n,在光线0°入射条件下,则对于参考波长的有效光学厚度为( )。