Consider the following premises. Sarah is a nurse if and only if William is taking a plane. It is raining if and only if Sarah is a nurse. If it rains, then William is taking a plane. Can we infer the following from them? If it rains, then Sarah is a nurse.
 From the fact that Sarah is a nurse if and only if William is taking a plane we can infer that if William takes a plane, then Sarah is a nurse. Finally, from the fact that if it rains, then William is taking a plane, and that if William takes a plane, then Sarah is a nurse we can infer that if it rains, then Sarah is a nurse. Therefore, the answer is yes.