B1 Unit1.3

1. The tree crowns of the ___________ are oval-shaped.

• A. emergent layer
• B. canopy layer
• C. understorey
• D. shrub layer

2. Which of the following descriptions about the layered structure of tropical rainforests is INCORRECT?

• A. Five layers can be found.
• B. The tree crowns of the canopy layer form a continuous layer.
• C. The trees of the emergent layer are sparsely distributed.
• D. The shrub layer is composed of ferns and herbs.

3. Tropical rainforests are homes to two-thirds of the world’s plants and animal species.

• A. True
• B. False

4. Which of the following is the function of drip-tip leaves?

• A. To compete for sunlight
• B. To stand against strong winds
• C. To shed rainwater quickly
• D. To help absorb water

5. Which of the following is NOT a characteristic of the plant shown in the photo?

• A. It has buttress roots to support itself.
• B. It is a type of saprophytes.
• C. It cannot carry out photosynthesis.
• D. It absorbs nutrients from decaying leaves.