You ought to have put the milk in the refrigerator．Now ________ sour．

it smell

it is smelt

it smells

it is smelling

The goods ________ when we arrived at the airport．

were just unloading

were just been unloading

had just unloaded

were just being unloaded

A great number of colleges and universities ________ since 1949．

has been establish

have been established

have established

had been established

She will stop showing off if no notice ________ of her．

is taken

takes

will be taken

has taken

I promise that the matter will ________．

be taken care

be taken care of

take care

take care of

There are 100 teachers in our school, half of ________ are female．

which

whom

them

that

We should take action at once ________ it will be too late．

and

or

so

but

________ it to me and I will see what I can do．

When left

Leaving

If you leave

Leave

She had a very ________ manner．

relaxing

relaxed

relax

being relaxed

I will spend the weekend just ________．

relax

relaxed

relaxing

to relax