Cardiovascular exercise involves a. using major muscle groups b. working out for at least 5 minutes c. using slow, controlled breathing d. flexing the muscles quickly

The answer to this is C :). hope this helps

Her parents start noticing changes about her. she's probably just competive though not on drugs

Unlike  ct scans, which use x-rays,  mri scans  use powerful magnetic fields and radio frequency pulses to produce detailed pictures of organs, soft tissues, bone and other internal body structures.  differences between  normal and abnormal tissue is often clearer on an  mri  image than a  ct.you can see more with a mri scan. for example on an mri you can see internal bleeding.