单项选择题
The application of infrared scanning technolgy to agriculture met with some difficulties due to ______.( )
单项选择题 ——What do you think of his ______ play ( )——I like it much better than his ______ one.
单项选择题 In his example the author tells his readers that ______. ( )
单项选择题 Michael Creuse, ______ help Whymper climbed the Matterhom, was one of the first of the professional guides.( )
