When you are _______ about which button to press on the complicated machine, you can either read the user's guide for guidance or fax us for specific instruction. Don't ______ the trial-and-error method.     [ ]

A. insure; do  

B. ensure; make    

C. uncertain; try    

D. unsure; touch

眼正位另眼斜位，遮斜眼去遮双眼均不动；遮正位眼去遮，去遮眼从斜位到正位，另眼从正位到斜位，提示()
无论遮盖任一眼，去遮时均从斜位恢复正位，提示()
患眼注视时的偏斜角大于健眼注视时的斜视角，提示()
无论遮盖任一眼，未遮眼始终注视视标，被遮眼偏斜，去遮后双眼均不动，提示()
高度远视或高AC/A伴有低、中度远视，提示()

A．隐斜

B．恒定性斜视

C．交替性斜视

D．麻痹性斜视

E．调节性斜视