Thematic ielts reading practice tests toshkent «pir» nashriyoti – 2023 Cambridge English

Cambridge IELTS 9
TEST 186 
Questions 34 – 39
Complete the flow-chart below.
Choose 
NO MORE THAN TWO WORDS AND/OR A NUMBER
 from the passage.
Write your answers in boxes 
34-39
 on your answer sheet.
Method of determining where the ancestors of turtles and 
tortoises come from
Step 1:
71 species of living turtles and tortoises were examined and a total 
of 
34
.……………. were taken from the bones of their forelimbs.

Step 2:
The data was recorded on a 
35
.………………. (necessary for 
comparing the information).
Outcome: Land tortoises were represented by a dense 
36
.……………… of points towards the top. Sea turtles were 
grouped together in the bottom part.

Step 3:
The same data was collected from some living 
37
.……………… 
species and added to the other results.
Outcome: The points for these species turned out to be positioned 
about 
38
..……………… up the triangle between the land tortoises 
and the sea turtles.

Step 4:
Bones of R quenstedti and P talampayensis were examined in a 
similar way and the results added.
Outcome: The position of the points indicated that both these 
ancient creatures were 
39
.………………….

---

470
TEST 187 READING PASSAGE 1
You should spend about 20 minutes on 
Questions 4-8
 which are based on 
Reading Passage 1 below.
[Note: This is an extract from READING PASSAGE 1 about BAKELITE - The 
birth of modem plastics]
The term ‘plastic’ comes from the Greek plassein, meaning ‘to mould’ Some plastics 
are derived from natural sources, some are semi-synthetic (the result of chemical 
action on a natural substance), and some are entirely synthetic, that is, chemically 
engineered from the constituents of coal or oil. Some are ‘thermoplastic’, which 
means that, like candlewax, they melt when heated and can then be reshaped. 
Others are ‘thermosetting’: like eggs, they cannot revert to their original viscous 
state, and their shape is thus fixed for ever Bakelite had the distinction of being 
the first totally synthetic thermosetting plastic.
The history of today’s plastics begins with the discovery of a series of semi-
synthetic thermoplastic materials in the mid-nineteenth century. The impetus 
behind the development of these early plastics was generated by a number of 
factors - immense technological progress in the domain of chemistry, coupled with 
wider cultural changes, and the pragmatic need to find acceptable substitutes for 
dwindling supplies of ‘luxury’ materials such as tortoiseshell and ivory.
Baekeland’s interest in plastics began in 1885 when, as a young chemistry student 
in Belgium, he embarked on research into phenolic resins, the group of sticky 
substances produced when phenol (carbolic acid) combines with an aldehyde (a 
volatile fluid similar to alcohol). He soon abandoned the subject, however, only 
returning to it some years later. 8y 1905 he was a wealthy New Yorker, having 
recently made his fortune with the invention of a new photographic paper. While 
Baekeland had been busily amassing dollars, some advances had been made in 
the development of plastics. The years 1899 and 1900 had seen the patenting of 
the first semi-synthetic thermosetting material that could be manufactured on an 
industrial scale. In purely scientific terms, Baekeland’s major contribution to the 
field is not so much the actual discovery of the material to which he gave his name, 
but rather the method by which a reaction between phenol and formaldehyde could 
be controlled, thus making possible its preparation on a commercial basis. On 13 
July 1907, Baekeland took out his famous patent describing this preparation, the 
essential features of which are still in use today.
The original patent outlined a three-stage process, in which phenol and formaldehyde 
(from wood or coal) were initially combined under vacuum inside a large egg-shaped 
kettle. The result was a resin known as Novalak, which became soluble and malleable 
when heated. The resin was allowed to cool in shallow trays until it hardened, and then 
broken up and ground into powder. Other substances were then introduced: including 
fillers, such as woodflour, asbestos or cotton, which increase strength and moisture 
resistance, catalysts (substances to speed up the reaction between two chemicals 
without joining to either) and hexa, a compound of ammonia and formaldehyde which 
supplied the additional formaldehyde necessary to form a thermosetting resin. This resin 
was then left to cool and harden, and ground up a second time. The resulting granular 
powder was raw Bakelite, ready to be made into a vast range of manufactured objects. 
In the last stage, the heated Bakelite was poured into a hollow mould of the required 
shape and subjected to extreme heat and pressure, thereby ‘setting’ its form for life.

---

471