The Most & The Least

Is this sentence grammatically correct?

The most useful invention is a clock.

• Correct

• Incorrect

Is this sentence grammatically correct?

The least useful invention is a spinner.

• Correct

• Incorrect

Choose the correct sentence.

• The more interesting invention is a flip phone.

• The most interesting invention is a flip phone.

Which sentence is correct?

• The less interesting invention is an aqua treadmill.

• The least interesting invention is an aqua treadmill.

The ... useful invention is a fridge, because it keeps food fresh for a long time.

• more

• most

The ... useful invention is a hoverboard, because it makes you lazy.

• less

• least

The ... fascinating invention is the microwave oven. I always wonder how it works.

The ... fascinating invention are dog`s socks.

Re-arrange the words to make a sentence.

A / is / the / useful / engine / invention / car / most / .

Re-arrange the words to make a sentence.

least / . / spinner / a / interesting / The / is / invention