4 sentences

1. 蜜蜂在花丛中采集花粉。

   mì​fēng zài huā​cóng zhōng cǎi​jí huā​fěn.

   Bees are collecting pollen among the flowers.

   Source: Dong Chinese Dictionary

2. 蜜蜂正在忙着采集花粉酿蜜。

   mì​fēng zhèng​zài máng zhe cǎi​jí huā​fěn niàng mì.

   Bees are busy collecting pollen to make honey.

   Source: Dong Chinese Dictionary

3. 过敏性鼻炎在花粉季节非常普遍。

   guò​mǐn​xìng bí​yán zài huā​fěn jì​jié fēi​cháng pǔ​biàn.

   Allergic rhinitis is very common during pollen season.

   Source: Dong Chinese Dictionary

4. 由于花粉过敏，他一到春天就经常打喷嚏。

   yóu​yú huā​fěn guò​mǐn, tā yī dào chūn​tiān jiù jīng​cháng dǎ pēn​tì.

   Because of his pollen allergy, he often sneezes in the spring.

   Source: Dong Chinese Dictionary