2 sentences

1. 他的计划非常周密。

   tā de jì​huà fēi​cháng zhōu​mì.

   His plan is very thorough and meticulous.

   Source: Dong Chinese Dictionary

2. 我们应该事前做好周密的计划。

   wǒ​men yīng​gāi shì qián zuò hǎo zhōu​mì de jì​huà.

   We should make careful plans beforehand.

   Source: Dong Chinese Dictionary