We first met on a train in 2000.We both felt immediately that we _____ each other for years.
The old man __________ in Tibet for two years as a volunteer teacher;it is an experience he often mentions.
Qian Xuesen tried many times _________ he found the solution to the puzzle about space technology.
Those the exam cheat must another exam tomorrow afternoon.
He admitted a lie in order to avoid .
I your success although you are in difficulty now.