My teacher caught me sleeping in class and I ______ stay behind after class. (had to / can to)
had to
The radio _________ (invent) at the beginning of the 20th century.
was invented
I'm not just hungry, I'm _______!
starving
It makes / does sense to go to bed early the night before an exam.
makes
The planet Mars __________ during the next few years.
It's a really big secret, OK? You ____ tell anyone.
can't
In the First World War, radios ______ (use) to communicate with soldiers.
were used
It's not small, it's _______!
tiny
Yesterday I did / made a big effort and got up early!
made
Special robot vehicles _______ to investigate the planet's surface.
will be sent
I ______ come to your party. Mum says I'm not allowed to.
can't
Since the 1960s, many radio signals _____ (send) into outer space.
have been sent
freezing
You failed the exam? Don't worry, I'm sure you did / made your best.
did
It is possible that rocks and dust from Mars _______ back to Earth when the vehicles return.
will be brought
I'm not completely stupid, you know. You don't _______ explain everything to me!
have to
So far, no answers ______ (receive) from other plants.
have been received
That's funny. Actually, it's _______!
hilarious
He wants to do / make a lot of money.
make
These rocks ______ to find out if it is possible to live on Mars.
will be examined
______ you ______ wear a uniform to school?
Do....have to
It's possible that the signals have arrived on other planets, but the messages ______ (not understand).
Are you tired too? I'm absolutely _______.
exhausted
Drink this. I'll make / do you good.
The questions about the Red Planet ________ for a very long time.
won't be answered