The first time you read a text intensively:

• Focus on the content words (usually nouns, verbs, adjectives)

It is easy to read this by focusing on the content words in bold.

• Read in groups of two or more words (read phrases not words) eg subject + verb + object

At the age of 16 / most students take exams / in about ten different subjects

• Prepositional phrases

At the age of 16 / most students take exams / in about ten different subjects

• In complex sentences, identify and focus on the main clause

Vary your reading rate

Decrease speed when you find the following:

• An unfamiliar word not made clear by the sentence: Try to understand it from the way it’s used; then read on and return to it later.
• Long and uninvolved sentence and paragraph structure: Slow down enough to enable you to untangle them and get an accurate idea of what the passage says.
• Unfamiliar or abstract ideas: Look for applications or examples which will give them meaning. Demand that an idea “make sense.” Never give up until you understand, because it will be that much easier the next time.
• Detailed, technical material: This includes complicated directions, abstract principles, materials on which you have little background.

Increase speed when you find the following:

• Simple material with few ideas new to you:Move rapidly over the familiar.
• Unnecessary examples and illustrations:These are included to clarify ideas. If not needed, move over them quickly.
• Detailed explanation: Elaboration which you do not need can be scanned quickly.
• Broad, generalised ideas: These can be rapidly grasped, even with scan techniques.

Source: https://www.futurelearn.com/courses/pte-success/1/steps/930514