some grammar question?

Question

1.they had not cleaned the house for weeks and the health inspector found them living in the utmost __
A.contamination B.squalor
why choose B?i think A is also right. i am learning English.
2.after the outbreak of an unknown disease, investigation revealed__of the city's water supply.
A.contagion B.eruption(why choose A?)
3.his irresponsible behavior put the lives of all the workers in ___
A.harzard B.jeopardy (why choose B. ?)
4.the __ of the lakes is covered with reeds and rushes.
A.strand B.coast C.shore D. bank
(why choose C ?)
could you tell me how to use the words?

Answer 1

1.they had not cleaned the house for weeks and the health inspector found them living in the utmost __
A.contamination B.squalor

Squalor is right It is the state of being squalid, meaning filthy, foul, neglected, uncarred for, sordid and dingy.
Contamination means defiled by touching or infecting, to be polluted.
The property may have been dirty but still uncontaminated.

2.after the outbreak of an unknown disease, investigation revealed__of the city's water supply.
A.contagion B.eruption(why choose A?)

Contagion means transmission of disease. Eruption means brealing or bursting forth so Contagion would be appropriate.

3.his irresponsible behavior put the lives of all the workers in ___
A.hazard B.jeopardy (why choose B. ?)

Jeopardy is correct meaning to put into danger. Hazard means a risk or something that could cause an accident.

4.the __ of the lake is covered with reeds and rushes.
A.strand B.coast C.shore D. bank
Shore(s) is right as being land bordering sea or an expanse of water. A strand is a margin of sand, or beach, by a sea or a lake. A coast is a border of land next to a sea (not a lake). a bank is a mound or ridge or rising land by a river, lake or sea.

Hope that helps.

Answer 2

1.squarlor means "marked by filthiness and degradation from neglect or poverty" thus it fits in the first one.
2.contagion means"a disease-producing agent (as a virus)" thus it fits in the 2nd one.
3. jeopardy means "exposure to or imminence of death, loss, or injury : danger" and hazard means "danger" so i guess both r correct but 1st is more relevant.
4. shore and strand r synonyms and both can fit here

Answer 3

1. Contamination is the thing which is called so, when we have easily spread diseases.
2. Eruption is a thing which erupts, that is starts.
3. harzard is contamination( Difficlulty)
4.

Answer 4

1.squalor
2.contagion
3.jeopardy
4.shore