Examples should be given in plural

In English, examples should be given in plural. The following are some instances where such use is warranted.

1 Malaysia has a lot of seasonal fruit. These include durians, rambutans and langsats.

2 The furniture shop sells a variety of things such as sofas, chairs, desks, beds, mattresses and pillows.

3 I can see many items on display at the man's stalls. Examples of them are shirts, socks, neckties, singlets, handkerchiefs and gloves.

In your essay, if repeating the plural of a word seems monotonous, use the definite article for variety. Look at the following passage to show how you can break this monotony:
Computers have become part and parcel of our lives. In fact, this modern gadget has found its way into homes, offices and factories. Undeniably the computer is here to stay.

In the above passage, I use 'computers', then 'this modern gadget' followed by 'the computer' to avoid using the same words in it.