... chúng b) A có nhóm OH, hydro nhóm OH linh động c) Xác định công thức cấu tạo D E d) D, E tạo thành từ A B tương ứng nào, có quang hoạt không? 2) Từ dầu mỏ, người ta tách hydrocacbon A(C10H1 6); B(C10H1 8) ... thêm sản phẩm C3H6O2(D) B tạo sản phẩm phụ C3H5ClO (E) Trên phổ hồng ngoại D E vân hấp thụ vùng 1500 – 1800 cm-1, phổ D có vân hấp thụ mạnh tù 3100 – 3400 cm-1 phổ E không có: a)...
... mended D old-aged 20 A clapped B attracted C lifted D needed 21 A involved B believed C praised D locked 22 A remembered B cooked C closed D cleaned 23 A smiled B regarded C suggested D naked ... reversed B choked C played D sentenced 25 A minded B hated C exchanged D old-aged 26 A proved B looked C stopped D coughed 27 A dated B changed C struggled D agreed 28 A scaled B stared C phoned ......
... they 14 can't you II -> It is very expensive ,isn't it? -> The film was very great, wasn't it? -> Jane, you haven't got a pen, have you? -> She has a lovely voice , doesn't she? -> Kate, you don't ... has a lovely voice , doesn't she? -> Kate, you don't know where Ann is , you? -> It doesn't look very good, does it? -> The bridge isn't very safe, is it? III Your brothe...