2026年真题03

Listen to a talk on a biology podcast. Picture a creature that's smaller than a mouse, yet as territorial as a lion. Does it sound like a cartoon character? It's actually the real life Scarlet badis, A freshwater fish. It's only about 2 cm long at most. In the wild, it generally thrives peacefully in the slow moving streams of India. Because of its size and attractive coloring, it's also a popular choice for aquariums and fish tanks. However, in captive environments like aquariums, males are more aggressive. They'll chase and nip at other males if they encroach on their territory, so it's crucial to include lots of vegetation. Plants act as hiding places and borderlines between males territories. Now, male Scarlet badis are a vivid orangish red scarlet with light bluish stripes. When a male isn't having a confrontation with another male in the aquarium, though, his scarlet is less bright. It can almost but not quite resemble female coloring, which is dull gray. This could make it hard to tell the sexes apart, except if you can see any scarlet at all on the fish, it's a male. Plus, unlike in most fish species, males are also usually a bit larger than females. And the other time a male Scarlet basis shows his brightest coloring is during breeding season in aquariums, he can be observed doing a sort of dance to impress females, showing himself off. His dance also involves following the female around until she decides whether to mate with him.

Listen to a talk in a physics class. We've been talking about the law of inertia. An object moving in a straight line will continue to move in a straight line unless it is acted upon by another force. So what does this mean in the real world? Let's look at something many people do all the riding a bicycle. Think about riding along in a straight line. Once the bike is moving, inertia will keep it going in a straight line.But we don't just ride in straight lines, do we? We turn at corners and steer around things that are in our way. So how do you get the bicycle not to go straight? Easy, right? Don't you just need to turn the front wheel in the direction you want to turn? In fact, if you only turn the front wheel, you're likely to end up on the pavement.The wheel will turn, but because of inertia, your body and the rest of the bike will want to keep moving straight ahead. So how does a cyclist avoid this? The key is to lean in. Weight needs to shift in the direction of the turn so that the force of gravity can work against the force of inertia. Professional cyclists who move at high speeds need to hit a sweet spot. They must lean more to keep their bicycles from sliding out of turns, but not too much.At a certain point, gravity will bring both rider and bicycle down to the ground.