In animals like Annelids, Molluscs, organs have associated to form functional systems, each system concerned with a specific physiological function. This pattern is called ________ system level of organization.
In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select 'No Error'. My brother finds it difficult (1)/ to pass away the time (2)/ at our grandparent's house. (3)/ No Error (4)