The cactus is a plant which grows in very hot, dry places. Cacti do not have leaves. Instead, they have spiny needles which stick out of their stems. There are many shapes of the cactus. Some are small and round. Others are tall like columns or pillars Some are shaped like tubes or bells. Some are shaped like wheels. Some grow as trees or shrubs. Others grow as ground cover. Cactus flowers are big, and some of them bloom at night. Their flowers come out at night because they are pollinated by insects or small animals that come out at night. Insects and small animals carry pollen from one cactus to another.

In the passage above, them refers to:

a) cacti

b) flowers

c) ground cover

d) needles

The Voyager 1 and 2 spacecrafts left Earth in 1977 on a five-year mission. Their mission was to reach Jupiter and Saturn and send information back to earth about them. Jupiter and Saturn are the largest planets in the solar system. In 1981, they finished their mission. But, they kept going. Scientists decided to plan a longer trip for them: they would travel even further until they reached Uranus and Neptune. Voyagers 1 and 2 are very efficient. They were built with no moving parts. They use the breakdown, or the decay, of the space element “plutonium” to create fuel. They can each get the equivalent of 30,000 miles per gallon of gasoline! They were made to be able to work in radioactive environments. The “gas giants” – Jupiter, Saturn, Uranus, and Neptune – are very radioactive places.

According to the article:

a) Scientists discovered Uranus and Neptune had radioactive gases.

b) The spacecrafts are effective and have no components that move.

c) The largest planets create fuel for the spacecraft.

d) The spacecrafts had accomplished their missions and were then terminated.

Some animals hibernate or go into a deep sleep as an adaptation to the cold months of winter. Hibernation is different from normal sleep. During hibernation, an animal seems to be dead. Its metabolism slows down and its body temperature drops. Its heartbeat slows to only two or three beats a minute. Since its bodily processes are so slow, it needs very little food to stay alive. Some animals which hibernate are toads, skunks, ground squirrels, bees, and bats. Bears sleep during the winter, but they are not true hibernators. They wake up when they hear loud noises.

According to the passage, which of the statements is true?

a) All animals that sleep during the winter are authentic hibernators.

b) Only mammals hibernate.

c) An animal’s metabolism during hibernation is the same as when it is not hibernating.

d) Hibernation is a way of adjusting to the climate.