Final answer:
Under common law, Adele may be liable for Roger's injuries since she engaged in willful or wanton misconduct by deliberately covering a hole with brush, potentially indicating an intent to harm trespassers or reckless indifference.
Step-by-step explanation:
Under common law, the general rule is that landowners owe no duty to trespassers to maintain their property in a safe condition. However, there are exceptions to this rule for cases involving willful, wanton, or reckless conduct by the landowner. If Adele deliberately covered a deep hole with brush to conceal it, it may be regarded as willful or wanton misconduct, especially if it can be proved that she intended to harm trespassers or was indifferent to the consequences. Therefore, based on the information provided, the statement that Adele is liable for Roger's injuries because she concealed the hole with brush can be considered True, as her actions may fit the exception to the general rule under common law.