Third parties play a highly important role in the: strengthening of the two major parties weakening of the two major parties

The answer is: Strengthening the two major parties"

Third parties very rarely obtained a dominant vote in american election. But, when the third party realized that they had no chance in winning the election, it can opt to join with other major parties.

When this happen, the vote for the third party would be transferred to one of the major party and strengthen its position in the election.

what's this it's not giving you what have to do.

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.