Lǎoshī ràng wǒmen yòng míngyù miáoxiě yíxià qiūtiān de tiānkōng.
The teacher asked us to describe the autumn sky using a simile.
Tips
usage
明喻 'open comparison' names its comparison word: 他壮得像一头牛 'he is as strong as an ox'. A metaphor drops it and is called 暗喻 or 隐喻. Both are kinds of 比喻, the general word for a figure of comparison.