4 sentences

1. 组委会正在筹备国际马拉松赛。

   zǔ​wěi​huì zhèng​zài chóu​bèi guó​jì mǎ​lā​sōng​sài.

   The organizing committee is preparing for the international marathon.

   Source: Dong Chinese Dictionary

2. 组委会向所有参赛选手发给了入场证。

   zǔ​wěi​huì xiàng suǒ​yǒu cān​sài xuǎn​shǒu fā​gěi le rù​chǎng​zhèng.

   The organizing committee issued entry passes to all the contestants.

   Source: Dong Chinese Dictionary

3. 组委会正在向社会公开征集标志设计。

   zǔ​wěi​huì zhèng​zài xiàng shè​huì gōng​kāi zhēng​jí biāo​zhì shè​jì.

   The organizing committee is publicly soliciting logo designs from the community.

   Source: Dong Chinese Dictionary

4. 由于天气原因，组委会不得不调整了赛程。

   yóu​yú tiān​qì yuán​yīn, zǔ​wěi​huì bù​dé​bù tiáo​zhěng le sài​chéng.

   Due to weather conditions, the organizing committee had to adjust the schedule.

   Source: Dong Chinese Dictionary