第2题: [单项选择]大鼠出生后饲以去脂饮食,结果将引起下列哪种脂质缺乏 A. 磷脂酰胆碱 B. 甘油三酯 C. 鞘磷脂 D. 胆固醇 E. 前列腺素 参考答案:E 答案解析: 人体内的不饱和脂酸主要包括油酸、软油酸、亚油酸、亚麻酸和花生四烯酸等。前2种可自身合成,后
3种必需从食物中摄取,因此称必需脂酸。幼鼠饲料中缺乏必需脂酸时,其生长缓慢,皮肤不正常,有鳞屑状
第12题: [单项选择]Questions 18-21 are based on the following dialogue.How does David go back home from the store A. On foot. B. By bike. C. By car. D. Jane offers him a lift. 参考答案:A 答案解析:[听力原文]18-21 W: David, can I give you a hand with one of those grocery bags M: Sure, Jane. Cou
第26题: [单项选择]Remember that customers don't ______ about prices in that city. A. debate B. consult C. dispute D. bargain 参考答案:D 答案解析:[解析] A项debate意为“争论,辩论”;B项consult意为“咨询,商量”;C项dispute意为“争论,争执,对……提出质疑”,D项bargain意为“对……讨价还价”。
第31题: [单项选择]Why was Dr. Johnson driving carefully A. He was a new driver. B. The weather was very bad. C. It’s too dark. 参考答案:B 答案解析:[听力原文]13-16 Nearly at nine o’clock in the evening, suddenly the telephone was ringing. Dr. Jo