1. A competition is held in the forest, and two of the lion, tiger, leopard, and elephant need to be sent to participate. If the lion is sent, then the tiger must also be sent; if the leopard is not sent, then the tiger cannot be sent either; if the leopard participates, the elephant is unwilling to go. So, who will finally be able to participate in the competition? ( ).
(A) Lion, Tiger
(B) Tiger, Leopard
(C) Lion, Leopard
(D) Tiger, Elephant
【Answer】B
【Question Type】Logical Reasoning, Contrapositive Proposition
【Analysis】In logical reasoning, if the original proposition holds, then the contrapositive proposition also holds.
Starting from the question:
(1) If the lion goes, then the tiger goes; contrapositive: If the tiger does not go, then the lion does not go.
(2) If the leopard is not sent, then the tiger is not sent; contrapositive: If the tiger is sent, then the leopard must be sent.
(3) If the leopard is sent, then the elephant is unwilling to go; contrapositive: If the elephant goes, then the leopard cannot be sent.
From (2), we can see that the answer is B.
The question requires two animals to go. We can use the assumption method. If the lion goes, then the tiger goes, and if the tiger goes, then the leopard also goes. Three animals going is a contradiction, so the lion does not go. If the leopard does not go, then the tiger does not go, leaving only the elephant to go, which is a contradiction. Therefore, the leopard goes. If the leopard goes, then the elephant does not go. From the requirement that two animals go, we conclude that the tiger must go. Therefore, the answer is $\mathrm{B}$, the leopard and the tiger go.