Answer:
Bi (Bismuth)
Ag (Silver)
Li (Lithium)
Explanation:
Xe (Xenon) and I (Iodine) are non-metals. They cannot from a metallic bond because metallic bonds are bonds between metals only.
I'm thinking D. It seems to be the most plausible answer here
Carbon dioxide and Oxygen are the two gases of air which dissolves in water by diffusion The oxygen is dissolved in water so that fishes can take in oxygen through water to breathe, this is the biological importance of this process in nature. ... Fizzy drinks contain carbon dioxide dissolved in water.
Answer : Oxidizing agent is
and Reducing agent is 
Explanation :
The given unbalanced redox reaction is,

In acidic medium, the balanced redox reaction is,

Oxidizing agent : Oxidizing agents are those agent which oxidizes other substance and itself get reduced.
Reducing agent : Reducing agents are those agent which reduces other substance and itself get oxidized.
In this redox reaction,
is an oxidizing agent and
is a reducing agent.
The redox reaction is also shown below.