【单选题】I don’t think ___ of his parents are home. They usually go out for a walk at the moment. [ ]
【判断题】If buyers expected the future price of a good to decrease, it would tend to increase the current quantity exchanged.
【单选题】液压泵的( )是在不考虑泄漏的情况下,单位时间内泵所输出的液体的体积。
【单选题】感染HIV后,下列哪项不是导致机体免疫功能受损的主要机制( )
A.
被感染的CD4+淋巴细胞表面表达gp120,可与其他CD4+细胞相互融合,细胞被破坏
C.
HIV感染B细胞,能使其大量破坏,抗体生成减少
E.
感染HIV后诱发机体的免疫反应,使受感染细胞受到攻击而被破坏
【简答题】A.He tries on some other things that the others think best. B.He usually doesn't buy anything. C.He spends hours having a look round. D.He buys it so long as its color is right.