A nurse is reviewing prenatal care with a client. Which of the following statements by the client best expresses adequate understanding of nutritional needs during pregnancy

A. "I expect to gain a few pounds each month at first. Then I’ll really get big and put on 20 pounds or so. "
B. "I guess I will get big and gain 20 to 30 pounds and look pregnant."
C. "Because I have to eat for two, I should eat whatever I want whenever I feel hungry. "
D. "I will need to eat more so that I will gain about 25 pounds, but I want to make sure I don’t fill up with junk food. "

以学历教育为主的（）系统和以继续教育、岗位培训为主的（）系统是气象教育、培训体系的主体。