2 sentences

1. 这棵大树在地上投下了一大片浓密的荫。

   zhè kē dà​shù zài dì shàng tóu​xià le yī dà piàn nóng​mì de yìn.

   The large tree cast a large, thick shadow on the ground.

   Source: Dong Chinese Dictionary

2. 古人通过圭表投下的影子来确定冬至和夏至。

   gǔ​rén tōng​guò guī biǎo tóu​xià de yǐng​zi lái què​dìng Dōng​zhì hé Xià​zhì.

   The ancients determined the winter and summer solstices by observing the shadows cast by the gnomon.

   Source: Dong Chinese Dictionary