Give a summary of the effectiveness criteria when selecting a fitness center

Can anybody me fill in these blanks? ? you so much if u can!

Explain how unhealthful weight loss or weight gain can lead to further weight loss or weight gain.

Will treating a viral infection with antibiotics affect the course of the infection? a) no; antibiotics work by inhibiting enzymes specific to bacteria. antibiotics have no effect on eukaryotic or virally encoded enzymes.b) no; antibiotics do not kill viruses because viruses do not have dna or rna.c) yes; antibiotics activate the immune system, and this decreases the severity of the infection. d) yes; antibiotics can prevent viral entry into the cell by binding to host-receptor proteins.