-- Tom  it's too late. Our son ________&nbsp

问题补充：

--Tom,it'stoolate.Ourson________beback.--Don'tbeanxious.Idaresayhe________havesomeextraworktodo.A.can; mustB.will; mightC.should; mustD.must; may

答案：

C解析

C(解析：考查情态动词。should "按理说，应该” must “肯定”，选C。)