红细胞膜蛋白的遗传性缺陷常见于()
A.收缩蛋白
B.带3蛋白
C.4.1蛋白
D.锚蛋白
E.以上全部
参考答案:E
路基压实中,各种压路机的碾压行驶速度最大不宜超过()。
A.2km/h
B.3km/h
C.4km/h
D.5km/h
Which of the following statements about a monopolist is least accurate()
A. The monopolist faces a downward sloping demand curve.
B. Unlike an oligopolist, a monopolist will always be able to earn economic profit.
C. A profit-maximizing monopolist will expand output until marginal revenue equals marginal cost.