B1 - Present Simple or Present Continuous?

Some kinds of fish (a)   (contain) high levels of dangerous metals. 

Loud music can be really detrimental to the ears. Some people (a)   (not realize) its harmful effects.

A package holiday (a)   (cost) less than going on holiday on your own.

Technicians report that they (a)   (have) difficulty about the new computer system at the moment.

No wine for me! I (a)   (take) antibiotics for an ear infection.

Don’t worry about your dog! The vet (a)   (feel) his legs to check that nothing is broken right now.

The National Theatre (a)   (think) of putting a new production of Hamlet.

We (a)   (see) the bank manager this afternoon.  We have an appointment.

That girl (a)   (look) like your sister.

I (a)   (not understand) you. Could you speak more slowly?