急问。。。谢谢

fbfamous

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）

(E) Using a Doppler ultrasound device, a physician can detect fetal heartbeats by the twelfth week of pregnancy

不明白ETS的C解释，伴随结构向来是与谓语动作同时存在的状态啊，ETS为啥说有个先后顺序？？NN帮我

fbfamous

fbfamous

继续顶

古镯

C中的主次颠倒，把原先表方式的动词改为主句的谓语动词，主要动作却放在从属位置，变成了

a physican 通过 detecting fetal hearbeats... 能够使用 a Doppler ultraound device.

其实翻译成中文后, 也不合理.“通过探测胎音，医生使用一种仪器”

BTW: 提一点小小的建议哦，请附题号发贴，这样方便大家的学习，和后人的搜索！

fbfamous

其实题明白，就是不知道OG的解释是怎么回事

谢谢古镯，我以后会注意的，这些帖也改名字了