microscopic plant

例句：

1. 1.This plant is so small that it can only be seen with a microscope.
   这种植物非常小，只能用显微镜才能看到。
2. 2. Microorganisms are the smallest living things on Earth.
   微生物是地球上最小的生命体。
3. 3. The microorganisms play an important role in maintaining ecological balance.
   微生物在维持生态平衡中起着重要作用。