worried about :something that worries you

heart:something that is inside your body and makes you live

still:not moving or making a sound

grow :of a living thing) undergo natural development by increasing in size and changing physically; progress to maturity

bad grade: is for a bad qualification

throughout:in every part of (a place or object).

interested in : having the attention engaged interested listeners.

good at :One of the numerous meanings of good is “competent, skillful, clever at or in a certain action or pursuit.” The two expressions in the reader's question are often used interchangeably, but generally speaking, “good at” is used with

mri scans :a medical examination performed using magnetic resonance imaging.

brain:an organ of soft nervous tissue contained in the skull of vertebrates, functioning as the coordinating center of sensation and intellectual and nervous activity.

crawly legs :Restless legs syndrome (RLS) is a condition that causes an uncontrollable urge to move your legs, usually because of an uncomfortable sensation. It typically happens in the evening or nighttime hours when you're sitting or lyin

better at:of a more excellent or effective type or quality

afraid of:feeling fear or anxiety; frightened.