单项选择题 YL-335B生产线检测左料盘和右料盘是否有零件的传感器是( )。A. 对射式光电传感器B. 漫射式光电传感器C. 光纤传感器D. 电感传感器

问答题 Part 1. Complete the sentences below with the words in the box. Change the form where necessary. Each word can be used only once. （20 points, 2 points each）   device    mode   contrast   campaign    assess    plagiarism undermine    exemplify     access     acquire 2. Most students attend a university mainly to _________ the knowledge needed for their chosen profession.

单项选择题 DPSK属于： A、相位调制 B、幅度调制 C、频率调制 D、混合调制