Consider the following premises. s_2 or ~u. u or ~q_2. Can we infer q_2 -> s_2 from them?
 From s_2 or ~u we can infer u -> s_2. From u or ~q_2 we can infer q_2 -> u. Finally, from q_2 -> u, u -> s_2 we can infer q_2 -> s_2. Therefore, the answer is yes.