Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 33 to 37.

All plants rely on nutrients taken from the soil in order to survive. However, in areas where the soil does not contain enough (33) _____ nutrients, some plants have adapted to supplement their diets from another source: living organisms. Though they are few in number, carnivorous plants are (34)_____ fascinating beings that “eat” anything from one-celled organisms to insects in order to survive. They are commonly found in marshlands. Carnivorous plants feature one of several types of “traps” to ensnare prey, which they consume to make up for nutrients that may be missing from the soil. While there are over 400 species of carnivorous plants in the world today, some are more prevalent than others.

The most well-known of these plants are the snap traps, which include the Venus flytrap. Snap traps are easily identified by their leaves, which are separated into two lobes that have the ability to fold together. Inside the lobes, the surface is covered with tiny hairs that are (35) _____ to movement. When the plant’s prey brushes against the hairs, it triggers a closing mechanism that rapidly brings the two lobes together, trapping the prey securely inside. The response of the traps is phenomenal (36)_____ speed: the time between triggering the hairs and snapping shut is less than a second. As the prey struggles inside the trap, it only triggers more hairs, causing the leaves to tighten their grip. The plant then secrets liquid chemicals from special glands into the trap to dissolve the prey and absorb all of its nutrients. Besides the Venus flytrap, only one other type of snap trap exists today, (37)_____ to as the waterwheel plant. The two share a common ancestor and differ only in a few ways. For instance, the waterwheel is an aquatic plant, while the flytrap is exclusively terrestrial. In addition, the flytrap feeds primarily on arthropods like spiders, while the waterwheel lives off simple invertebrates, like certain types of plankton.

Điền vào số (34)

If he _____ harder, he would have passed the exam