Win the PTE marks you can practise exactly.

Coral bleaching

Reef-building corals live in partnership with microscopic algae that occupy their tissues and supply much of their food through photosynthesis. When the surrounding water stays unusually warm for several weeks, this partnership (1) ______: the stressed coral expels the algae, and because the algae give the coral most of its colour, the animal turns pale. A bleached coral is not yet dead, but it is (2) ______ to disease and starvation. If temperatures return to normal quickly, the algae can recolonise the tissue and the coral may (3) ______. Repeated events, however, leave too little time for this recovery, which is why scientists regard the (4) ______ of marine heatwaves, and not only their intensity, as a key threat to reefs.

Roman roads

Roman roads are often admired as feats of engineering, built with layers of stone and gravel and laid out in long straight lines. It is easy to forget why the state invested so heavily in them. The roads allowed armies to move quickly between provinces, and official messengers used them to carry orders and reports. Trade and private travel certainly benefited, but these were largely side effects of a network designed to hold a large empire together.

The discovery of penicillin

Put the sentences in the right order. Topic: The discovery of penicillin.

The origins of writing in Mesopotamia

Writing appears to have been invented independently in several parts of the world, but one of the earliest known systems developed in southern Mesopotamia, in what is now Iraq, more than five thousand years ago. Its origins were surprisingly practical. The first inscriptions were not poems, laws or histories but administrative records, kept by officials of temples and cities who needed to track grain, livestock, labour and other goods.

Before writing, accountants in the region used small clay tokens of different shapes to represent quantities of goods. Many scholars believe that marks pressed into clay to stand for these tokens gradually developed into signs. Early signs were often pictures of the thing counted, combined with marks for numbers. Over the following centuries, the signs became more abstract and were made by pressing a reed into wet clay, producing the wedge-shaped marks that give cuneiform its name, from the Latin word for wedge.

A major step came when scribes began to use signs for their sounds as well as their meanings. This allowed them to write names, grammatical endings and eventually whole sentences of spoken language. Cuneiform was later adapted to write many different languages across the Near East and remained in use for around three thousand years.

Learning the system was demanding, since it used hundreds of signs. Scribes trained for years in schools, copying lists of signs and model texts, and literacy remained limited to a small professional group. Much of what we know about these schools comes from the clay tablets themselves, which survived in large numbers because baked or sun-dried clay is extremely durable.