Can I ________ a try?[ ]
A. has
B. have
C. had
D. he
答案：B
My friend Tom comes from Canada and _______ is a tall boy with blue eyes. [ ]
A. he
B. his
C. she
D. it
对射式的光电传感器的发射器尽可能精确地与（）对齐。
A、接收器
B、光板
C、开关
D、滤波器
