下列情境说话，用语得体的一项是（ ）

Without my glasses, I couldn’t _____ whether that figure on the blackboard was a three or an eight.

(2013·重庆模拟)—When did your brother begin to show his interest in medicine? —It was a Saturday　　　he noticed his classmate experimenting on a frog in the lab.

Zhanglin was lost in computer games during his last year in high school, otherwise he _____ a student at Beijing University.

Light doesn’t travel as fast as sound,_______