3 sentences

1. 蓝天衬着洁白的云朵。

   lán​tiān chèn zhe jié​bái de yún​duǒ.

   The blue sky sets off the pure white clouds.

   Source: Dong Chinese Dictionary

2. 云朵像白棉花一样大朵大朵地挂在天上。

   yún​duǒ xiàng bái mián​hua yī​yàng dà duǒ dà duǒ de guà zài tiān shàng.

   Large clouds hung in the sky like white cotton balls.

   Source: Dong Chinese Dictionary

3. 深秋的天总是那么高，那么蓝，看不见一丝云朵。

   shēn​qiū de tiān zǒng​shì nà​me gāo, nà​me lán, kàn bù jiàn yī sī yún​duǒ.

   The late autumn sky is always so high and blue, without a single cloud in sight.

   Source: Dong Chinese Dictionary