RULE: To make guesses about the , we use must, might (not), can’t or could (not) + have + . 1 Jane left without saying a word. She___must have been (be) very angry.
2 We don’t know where they got the stones from, but they can`t have brought (not bring) them from somewhere far away. They’re too heavy.
3 They recently found an ancient site in Peru. It’s almost 3000 years old and it(be) a religious site, but we can’t be sure.
4 I had my wallet an hour ago, but it’s not here now. I (leave) it in that shop!
5 Sally hasn’t called me. She (not get) my text message.
6 Somebody(take) the book from her bag. Or maybe she left it on the bus.

Это текст
1 Stonehenge, England
The stone ring at Stonehenge is a famous sight for tourists in Britain. But there are a lot of questions about it that we can’t answer. One thing we do know about Stonehenge is that it was started around 5000 years ago, and completed 3500 years ago. Experts think that originally there were 30 stones, but only 17 remain standing. The main thing that we don’t know about Stonehenge is why it was put there. There are many theories – perhaps it was a religious place, or it might have been a place for observing the stars and planets. We don’t know for sure. And we also don’t know how Stonehenge was built. Some of the stones came from 200 kilometers away and some of them weigh 40 tons – a tremendous weight. It can’t have been easy to get these huge stones into an upright position, but we think that workers must have used ropes to pull them up. But how did the stones get there in the first place?
2 The Pyramids of Giza, Egypt
Just outside the huge metropolis of modern-day Cairo, we can see the Great Pyramids of Giza. Built around 4500 years ago, they have stood for centuries looking out over the desert. We know why they were built – they are enormous tombstones, marking the burial place of some of the Pharaohs of ancient Egypt. But there is still some mystery surrounding them: exactly how were they built?
The biggest pyramid – which marks the burial place of the pharaoh Khufu, and is 147 metres high – consists of around two million blocks of stone. Each one weighs around two tons. The stone was taken from the ground and transported along the River Nile to Giza. Then it was carried, cut into blocks and lifted to build the pyramids. This was an amazing achievement – even today, it wouldn’t be easy to do, so it must have been incredibly difficult then. And who did it? Some people think the Egyptians might have used slaves to move the stones, but experts now believe that it must have been done by tens of thousands of skilled workers.