4 sentences

1. 这种微处理器主要用于处理定点运算。

   zhè zhǒng wēi​chǔ​lǐ​qì zhǔ​yào yòng​yú chǔ​lǐ dìng​diǎn yùn​suàn.

   This microprocessor is mainly used for fixed-point calculations.

   Source: Dong Chinese Dictionary

2. 圆是平面上到定点距离等于定长的点的轨迹。

   yuán shì píng​miàn shàng dào dìng​diǎn jù​lí děng​yú dìng​cháng de diǎn de guǐ​jì.

   A circle is the locus of points in a plane that are at a fixed distance from a fixed point.

   Source: Dong Chinese Dictionary

3. 大巴车会在定点时间和地点接送员工。

   dà​bā​chē huì zài dìng​diǎn shí​jiān hé dì​diǎn jiē​sòng yuán​gōng.

   The bus picks up and drops off employees at designated times and locations.

   Source: Dong Chinese Dictionary

4. 救援人员正尝试通过卫星信号进行定点。

   jiù​yuán rén​yuán zhèng cháng​shì tōng​guò wèi​xīng xìn​hào jìn​xíng dìng​diǎn.

   Rescuers are trying to pinpoint the location via satellite signals.

   Source: Dong Chinese Dictionary