हड्डियों के असामान्य रूप से सख्त होने और अस्थि घनत्व (bone density) में वृद्धि को किस रूप में जाना जाता है?

Which of the following groups consists exclusively of diseases caused by bacterial infections?

Which of the following groups of biological agents are the primary carriers in contaminated water that cause waterborne diseases such as cholera, typhoid fever, and dysentery?

Identify the bacterial disease from the following options: