1. PART A: Which of the following best describes the author's main claim in the text
O A Water scarcity is not something that humans have
any control over, as it is caused by natural events,
B Humans can reverse the damage they have inflicted
on the Earth's water supplies if they reduce their
pollution output
C Widespread water scarcity threatens the right that
all humans should have to access dean drinking
water, as it is essential to live,
D Water scarcity is an issue primarily caused by
humans that needs to be addressed by humans.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

indicate valleys, hills, steepness and gentleness of slopes.

explanation:

contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.