第4题: [单项选择]患儿男,2.5岁,出生后3天发现血便,查血常规发现血小板为8×109/L,此后血小板波动于5~30×10/L。常患感冒,约每月1次,表现为发热、咳嗽、咳白色泡沫痰,偶于头面部出现红色斑丘疹,伴瘙痒。其病因是() A. Btk基因突变 B. 血小板抗体产生 C. WASP基因突变 D. 染色体畸变 E. γc基因突变 参考答案:C
第17题: [单项选择]Questions 19 to 22 are based on the conversation you have just heard. A. They are virtually impossible to enforce. B. Neither is applicable to the woman’s case. C. Both of them have been subject to criticism. D. Their requirements may be difficult to meet. 参考答案:D 答案解析:What does the man say about the two federal laws?
第18题: [单项选择]串激电动机的转矩随转速变化的规律是(). A. 低转速时转矩大,高转速时转矩小 B. 低转速时转矩大,高转速时转矩大 C. 低转速时转矩小,高转速时转矩小 D. 低转速时转矩小,高转速时转矩大 参考答案:A