第18题: [单项选择]The technology supplied by Motorola is based on ______. A. Bluetooth features B. MP3 audio capability C. Global Positioning System D. GPRS standard 参考答案:D 答案解析:根据第二段第二句话“Motorola said it will begin offering the technology based on the next-generation GPRS (Glo
第19题: [单项选择]REM睡眠约占总睡眠时间的比例为() A. 5%~10% B. 10%~15% C. 15%~20% D. 20%~25% E. 25%~30% 参考答案:D
第20题: [单项选择]原位菌群失调分为几度 () A. 2 B. 3 C. 4 D. 5 E. 6 参考答案:B