We regret ______ unable to agree to the buyer's request as stated in the L/C stipulations for insurance to becovered up to the inland city.
While I was waiting for her ,I killed time____looking in the show windows.
Which one is not the functions of the nonverbal communication ;（）
We are now focusing on the adverse effects of work on health, although the positive effects of appropriate work on health and well-being are no less important.