Almost 300,000 teenagers in England, Wales and Northern Ireland will receive their A-level results later - but their grades are based on estimates as examinations were cancelled due to the coronavirus pandemic. The way the grades have been decided remains controversial, with a late change to the process being announced by ministers on the eve of results day. The "triple lock" means a student in England could get whatever was highest out of three assessments - their estimated grade, an optional written paper in the autumn, or an appeal through their school if the estimated result is lower than the mock exam. About 40% of the grades awarded on Thursday will be different from teachers' predictions.
Education Secretary Gavin Williamson has congratulated students on "getting through this extraordinary year" and promised that the class of 2020 will not lose out because of coronavirus. But he defended his decision to include mock exam results in the appeals process, saying that awarding grades based solely on teachers' predictions would "devalue" the results and be unfair on those who had taken exams in previous years. But students and teachers' leaders have criticised the move to include mock exam results, saying they are run in different ways by different schools. You can read one teenager's take on the use of mock exam results here.
As it stands, there has been a 2% rise in the number of A*s and As awarded this year at A-level, with more than a quarter of all students getting the top grades.
The next step for many of those students getting their A-levels will be university - and the admissions service Ucas says colleges will be "super-flexible" when it comes to helping teenagers who have missed out on their expected grades. About 25,000 places are set to be available through the clearing process.
Due to the pandemic, results day is going to be different this year - read just how different here. We've also answered some of your questions about this year's exams.

Investigators have begun their inquiry into how a train derailed in north-east Scotland, killing three people and injuring six others. The driver, conductor and a passenger on the 06:38 Aberdeen to Glasgow service died after the train left the tracks near Stonehaven on Wednesday morning. It is thought the train hit a landslide brought on by heavy rain. Officials from the British Transport Police, Rail Accident Investigation Branch and the Office of Road and Rail are leading the search for answers. The train drivers' union Aslef said that while it was too early to speculate on the cause of the crash, the carriages rolled down a steep embankment and caught fire.
The Queen, Scotland's First Minister Nicola Sturgeon and UK Prime Minister Boris Johnson have all sent messages of condolence. The UK and Scottish transport secretaries are also due to visit the scene.
The British Transport Police believes all those on board the train have been accounted for.

In their first joint campaign appearance, the Democratic Party's candidates for the White House have accused US President Donald Trump of "whining" and attacked his record on coronavirus, climate change, unemployment and race. Speaking at a socially-distanced press conference in Delaware, Mr Biden said the president had already begun his attacks on Ms Harris - a US senator from California - and accused Mr Trump of having "a problem with strong women". Ms Harris described the 3 November presidential election as a " moment of real consequence for America", adding that "the kind of country we live in" is on the line.
Mr Trump, a Republican who won in 2016, has disparaged Ms Harris's own attempt to gain the Democratic presidential nomination. At a press conference on Wednesday, Mr Trump said "there was no-one more insulting Biden than she was" during that campaign. If you want to know more about Kamala Harris, click here, and you can also read our analysis of whether she will help or hurt the Biden campaign.

Thursday's papers are dominated by the controversy over the awarding of this year's A-levels. The Daily Mail says exam grades are "in chaos" and the appeals process will be overwhelmed. The Guardian says teachers are "in despair" and fear that many students will have their results downgraded. Education Secretary Gavin Williamson has defended the process in the Daily Telegraph, which reports that he believes boosting grades will "harm Generation Covid for life". The Times takes a more positive note, reporting that universities will "throw a lifeline" to thousands of students who have their results downgraded. For more on this and other stories, here's our paper review.

It's been hot - uncomfortably hot for some. Central London has had six days where the temperature was more than 34C (93F) - the first time that has happened since 1961. But the heatwave is expected to come to a stormy end, with warnings of thunderstorms across many parts of the UK, and fears of flooding and travel disruption. Elsewhere, a musical based on the life of Diana, Princess of Wales, is to be shown first on streaming service Netflix rather than in a theatre on New York's Broadway. The decision has been brought about because of the pandemic, which has temporarily closed live entertainment venues.

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