ngotrung
14-07-2007, 12:39 AM
Before scientists learned how to make a synthetic growth hormone, removing it painstakingly in small amounts from the pituitary glands of human cadavers.
A. scientists learned how to make a synthetic growth hormone, removing it painstakingly
B. scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly
C. scientist learned how to synthesize the growth hormone, it had to be painstakingly removed
D. learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
E. Learning how to synthesize the growth hormone, it have to be painstakingly removed by scientists
Anh Trung chú ý lần sau gạch chân hay làm dấu hiệu gì để dễ nhận ra nhé.
A. scientists learned how to make a synthetic growth hormone, removing it painstakingly
B. scientists had learned about making a synthetic growth hormone, they had to remove it painstakingly
C. scientist learned how to synthesize the growth hormone, it had to be painstakingly removed
D. learning how to make a synthetic growth hormone, scientists had to remove it painstakingly
E. Learning how to synthesize the growth hormone, it have to be painstakingly removed by scientists
Anh Trung chú ý lần sau gạch chân hay làm dấu hiệu gì để dễ nhận ra nhé.