Sickle cell aneamia is more common in South Africa. This is due to
Change in $\beta$-chain of haemoglobin
More population of house flies
Change in $\alpha$ -chain of haemoglobin
Change in $\gamma$ -chain of haemoglobin
The artificial drug used as a sedative and to reduce the anxiety. It also induces the sleep. The drug is
Parasite which is vector host also is
Widal test is used for the diagnosis of
Intestinal perforation is the characteristic symptom of