The rise in sales of books is estimated to be 5%. The rise in sales of books is lower than the rise of sales in laptops.
Connect the two sentences, without repeating the subject =
The rise in sales of books is estimated to be 5%, which is lower than the rise of sales in laptops.
By using ‘which’ you are making two simple sentences into one longer complex sentence, which is what the examiner is looking for in the ‘Grammatical range and accuracy’ section of the marking scheme.
Do NOT forget that you need a COMMA before ‘which’. You have to imagine that ‘which’ is replacing the subject. As we know, EVERY ENGLISH SENTENCE NEEDS A SUBJECT, so this second part connected by 'which' is NOT a complete sentence (it is a relative clause) and needs to stay connected to the first sentence by a comma - NOT a full stop.
Look at the example of a mistake and how it has been corrected:
This report refers to a pie chart ⌃shows the main causes why agricultural land is becoming less productive.
Corrected:
This report refers to a pie chart, which shows the main causes why agricultural land is becoming less productive.
Try to connect these simple sentences by using ‘which’ and a comma.
There are a number of causes of land degradation. The causes of land degradation are shown on the pie chart.
There are a number of advantages and disadvantages. The advantages and disadvantages will be discussed in this essay.
Answers to the above questions:
There are a number of causes of land degradation, which are shown on the pie chart.
There are a number of advantages and disadvantages, which will be discussed in this essay.