Subject Verb Agreement and Present Continuous

Mark ______________ (is, are) excited.

He is about to ______________ (show, shows, showing) his friends his latest and most amazing science experiment.

Mark proudly ______________ (say, says, saying)....

Guys, today we are ______________ (go, goes, going) to see something incredible!

I am ______________ (turn, turns, turning) water into jelly with my secret formula.

His friends ______________ (is, are) curious.

His friends __________________ (watch, watches, watching) Mark with interest.

Mark is ______________ (pour, pours, pouring) a glass of water into a large beaker.

Then, he ______________ (add, adds, adding) a few drops of his special potion.

The water in the beaker is ______________ (start, starts, starting) to bubble and change colours.