Question

read the text
black mambas are fast, aggressive, and venomous. it is no wonder that they are considered one of the deadliest snakes in the world. in general, the snakes actually try to avoid confrontation. however, a perceived threat to a black mamba will result in several reactions meant to warn a potential victim. first, the black mamba raises its head, spreads out its neck-flap, opens its black mouth, and hisses. a threat that continues will lead to a more dangerous reaction: the mamba will bite its victim repeatedly, injecting its poisonous venom. for most of history, a mamba bite would mean certain death. today, though, an effective antivenom is available.
match causes with their effects.
cause
black mamba perceives a continuing threat.
black mamba perceives a new threat.
effect
black mamba hisses.
black mamba injects victim with venom.

Explanation:

To solve the cause - effect matching:

1. For the cause "Black mamba perceives a continuing threat", we look at the text. It says "A threat that continues will lead to a more dangerous reaction: the mamba will bite its victim repeatedly, injecting its poisonous venom." But also, when it perceives a new threat, let's check the other cause. Wait, the other cause is "Black mamba perceives a new threat". From the text: "a perceived threat to a black mamba will result in several reactions meant to warn a potential victim. First, the black mamba raises its head, spreads out its neck - flap, opens its black mouth, and hisses." So for "Black mamba perceives a new threat", the effect is "Black mamba hisses" (since the initial warning reactions include hissing). For "Black mamba perceives a continuing threat", the text says the more dangerous reaction is biting, so the effect is "Black mamba injects victim with venom".

Answer:

• Cause: Black mamba perceives a new threat; Effect: Black mamba hisses.
• Cause: Black mamba perceives a continuing threat; Effect: Black mamba injects victim with venom.