5 sentences

1. 这件工作真是费力不讨好。

   zhè jiàn gōng​zuò zhēn shì fèi​lì bù tǎo​hǎo.

   This task is a thankless job that requires a lot of effort.

   Source: Dong Chinese Dictionary

2. 登山者费力地爬上了那道陡岩。

   dēng​shān zhě fèi​lì de pá​shàng le nà dào dǒu yán.

   The climber struggled to scale the steep rock face.

   Source: Dong Chinese Dictionary

3. 他费力地举起了那个沉重的箱子。

   tā fèi​lì de jǔ​qǐ le nà​ge chén​zhòng de xiāng​zi.

   He lifted the heavy box with great effort.

   Source: Dong Chinese Dictionary

4. 他费力地把沉重的箱子往门外扯。

   tā fèi​lì de bǎ chén​zhòng de xiāng​zi wǎng mén wài chě.

   He struggled to drag the heavy box out the door.

   Source: Dong Chinese Dictionary

5. 爬山虽然很费力，但山顶的风景很美。

   pá​shān suī​rán hěn fèi​lì, dàn shān​dǐng de fēng​jǐng hěn měi.

   Although climbing is strenuous, the view from the top is beautiful.

   Source: Dong Chinese Dictionary