What did I do wrong?

Which type of computing device is best suited to having a digital pen as an input device? a. personal computer b. personal digital assistant c. smart television d. laptop e. mobile phone

Which of the following is a way that advancements in technology improve humans' ability to measure air quality and protect human health? a. air quality data gathered by new instruments can be used to reduce exposure to pollutants. b. new technologies enable natural and human-made pollution sources to be located and monitored. c. air quality data gathered by new instruments can be used to predict trends in pollution over time. d. new technologies allow governments to make informed decisions about the regulation of pollution. (choose more than one)

Two technicians are discussing the common u-joint. technician a says its input and output speeds should be equal. technician b says that it normally has two yokes. which technician is correct?