Sugar is uncountable; therefore, the sentence has a singular verb. Marbles are countable; therefore, the sentence has a plural verb. 3. Compound subjects joined by and are always plural. 4. With compound subjects joined by or/nor, the verb agrees with the subject nearer to it.
Panic disorder causes panic attacks spontaneous feelings of anxiety, terror, or impending doom. Physical symptoms include heart palpitations, chest pain, and shortness of breath. These attacks may be repeated at any time. People with any type of anxiety disorder may have panic attacks.
1 Anxiety affects a sufferer physically as well as mentally. Some physical symptoms, especially during a panic attack, include shortness of breath, shaking, nausea, headache, rapid heartbeat, dizzy spells, and more.  Surpassing even depression, anxiety is the most common form of mental illness in the United States. Itâs estimated that approximately 10 percent of teenagers and 40 percent of adults suffer from an anxiety disorder of some kind.