Which of the following statements is (are) false? i. vertebrate blood is a type of connective tissue. ii. plasma is composed mainly of water. iii. most infectious agents we breathe in are filtered through the tonsils. iv. lymph is returned to the circulatory system through ducts near the shoulders. i only ii only iii only iv only i and iii only

Answer is option (III) Most infectious agents we breathe in are filtered through the tonsils.

Explanation:

(I) In vertebrates, blood is considered to be a specialized form of a connective tissue. - TRUE

(II) Plasma is the liquid in the blood which contains the white blood cells, red blood cells  and the platelets and it is composed of about 90% of water. - TRUE

(III) Most infectious agents we breathe in are filtered and destroyed through the adenoids, which are the glands in the mouth connecting the nose to the throat. - FALSE

(IV) Lymphs are located in the right and left thoracic which return to the circulatory systems through the ducts near the shoulders.