What event started the gulf war in 1991?
a. the invasion of kuwait by iraq
b. the invasion of pakistan by india
c. the invasion of egypt by great britain
d. the invasion of afghanistan by the soviet union

The best answer is A.

Saddam Hussein who was the Iraqi leader at the time ordered the invasion of and occupation of Kuwait in August 1990.

Saddam Hussein defied United Nations  Security Council demands to withdraw  from Kuwait by Mid - January 1991. and the Persian Gulf war began with a massive U.S.  led air offensive called operation desert storm . After 42 days of relentless allied ground and air assault, the Iraqi army was in tatters  and President Bush declared a ceasefire on 28thFebruary 1991.

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.