Срочно! Поставить глагол в правельную форму. 1) The brain ( to be situated) in the skull. 2) the surgical operations (to be performing) by surgeons. 3) the blood type (to be determined ) by the blood test.

1) The brain is situated in the skull.2) the surgical operations are being performed by surgeons. 3) the blood type is determined  by the blood test.