Question

Turn off the water while you ________ your teeth or washing your hands.

A．were brushing	B．brush
C．are brushing	D．brushed

Answer 1

C

试题分析：句意：当你刷牙或者洗手时关掉水管。while引导的从句中常用进行时态。当主句描述将来动作时，条件从句中常用现在时态，故选C。