4 sentences

1. 精液中含有大量精子。

   jīng​yè zhōng hán​yǒu dà​liàng jīng​zǐ.

   Semen contains a large amount of sperm.

   Source: Dong Chinese Dictionary

2. 精子与卵子结合形成受精卵。

   jīng​zǐ yǔ luǎn​zǐ jié​hé xíng​chéng shòu​jīng​luǎn.

   The sperm and egg combine to form a fertilized egg.

   Source: Dong Chinese Dictionary

3. 这些鱼类通过排放精子来繁殖后代。

   zhè​xiē yú​lèi tōng​guò pái​fàng jīng​zǐ lái fán​zhí hòu​dài.

   These fish reproduce by releasing sperm.

   Source: Dong Chinese Dictionary

4. 受精卵是由精子和卵子结合而成的。

   shòu​jīng​luǎn shì yóu jīng​zǐ hé luǎn​zǐ jié​hé ér chéng de.

   A fertilized egg is formed by the union of sperm and ovum.

   Source: Dong Chinese Dictionary