og44，关于OG解释

44. Using a Doppler ultrasound device, fetal heartbeats can be detected by the twelfth week of pregnancy.
(A) Using a Doppler ultrasound device, fetal heartbeats 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：E

这道题我做对了。看过OG解释，我还有以下想法：

我感觉A是不是还有另一个错误，就是把by the twelfth week of pregnancy和fetal heartbeats分开了，放在了be detected 后面，造成歧义，好像是detected by the twelfth week of pregnancy了。但是OG的解释中并没有提到这一点，我不知道我的理解对不对。

而且，D也把by the twelfth week of pregnancy和fetal heartbeats分开了，把by the twelfth week of pregnancy放到了最前面，结构也很不好，就好像是作为某种方式修饰全句似的。

请大家都来看看吧，如果我的想法是错的，请帮忙指正。谢谢！

OG解释：Choice A presents a dangling modifier. The phrase beginning the sentence has no noun that it can logically modify and hence cannot fit anywhere in the sentence and make sense. Coming first, it modifies heartbeats, the nearest free noun in the main clause; that is, choice A says that the heartbeats are using the Doppler ultrasound device. Choice B contains the same main clause and dangling modifier, now at the end. Contrary to intent, the wording in choice C suggests that physicians can use a Doppler ultrasound device after they detect fetal heartbeats. In choice D the phrase using ... device should follow physician, the noun it modifies. Choice E is best.

恩，你说的对，A 选项中的  BY 不知道是方式   还是时间，所以混乱。 

D ，前面的部分和心脏病什么关系都没有，关键的问题是后面，using a Doppler ultrasound device    可以修饰 心脏病，也可以修饰医生   ，甚至可以修饰动作。

我的意见大家讨论

太好了，说明我的思路还正确

谢谢！