标题: [E]OG-44，请指点！ [打印本页] 作者: excellent 时间: 2004-1-19 09:49 标题: [E]OG-44，请指点！ 44. Using a Doppler ultrasound device, fetal heartbeats can be detected by the twelfth week of pregnancy. A.Using a Doppler ultrasound device, fetal heart-beats can be detected by the twelfth week of pregnancy. B.Fetal heartbeats can be detected by the twelfth week of pregnancy, using a Doppler ultrasound device. C.Detecting fetal heartbeats by the twelfth week of pregnancy, a physician can use a Doppler ultrasound device. D.By the twelfth week of pregnancy, fetal heartbeats can be detected using a Doppler ultrasound device by a physician. E.Using a Doppler ultrasound device, a physician can detect fetal heartbeats by the twelfth week of pregnancy.
答案是E。E中的by是什么意思？by the twelfth week of pregnancy这是一种什么样的表达方法？有谁能讲讲吗？
作者: rabbitbug 时间: 2004-1-20 18:54
by + 时间有两个意思： “在...时间内”和“到...为止”。 最好的分辨方法是句子的逻辑意思。 本题来说， 意思是“到怀孕的第12个星期为止， 医生就可以通过...东东探测出...”.这里的“by”就是“到...为止的”意思。 He sleeps by day. 意思是“他在白天睡觉”。作者: jzchina 时间: 2005-7-17 12:35
關於這道題的答案c，og的解釋是choice c suggests that physicians can use a doppler ultrasound device after they detect fetal heartbeats.選項c“Detecting fetal heartbeats by the twelfth week of pregnancy, a physician can use a Doppler ultrasound device.”是邏輯主語結構，主語主語是detecting...的邏輯主語，但是它們之間沒有先後關係的問題吧？請指點！
