lǎo / shī / yòng / xiǎn / wēi / jìng / ràng / wǒ / men / guān / chá / cǎo / lǚ / chóng / de / yùn / dòng老师用显微镜让我们观察草履虫的运动。The teacher used a microscope to let us observe how paramecia move.