How do we navigate in space?

Are humans naturally clean and tidy?

What exactly is this quantum computer?

Can smell and hiss your appetite?

Crayon science is the podcast that takes your science questions

and goes in search of the answers.

Stick with me because there's been some really fascinating research into this.

Find out more at the end of this podcast.

That is incredibly clever.

You're listening to the BBC World Service.

I'm Daniel Gordon and this is the breadline.

Over the next hour, you're going to be hearing from the men and women whose job, in normal times,

is to produce and transport a huge proportion of the wheat the world uses to make bread.

They live and work in Ukraine.

The world's fifth biggest exporter of wheat.

But of course, these aren't normal times in Ukraine.

They haven't been since Russia began what it calls its special military operation there, back in February.

President Putin has launched a big military offensive against Ukraine.

Russian troops and armour have cross-borders from the north, the east and the south.

Today at one where live in the Ukrainian capital Kiev,

with reports that Russian troops have reached the outer end.

Russian and Ukrainian armies are fighting fierce battles in several places close to Ukraine's capital Kiev

...