______ their service, the workers of the hotel are active in learning English.
| A．Improving | B．To improve | C．Improve | D．Having improved |
The conflict had developed into a stage ______ the two countries were gathering big troops on the border.
| A．where | B．when | C．which | D．that |
The schools themselves admit that not all children will be successful in the jobs ______ they are being trained.
| A．in that | B．for that | C．in which | D．for which |
______ scientists know where a storm will happen, winds will suddenly change, carrying the storm to a new direction.
| A．Even if | B．Since | C．Despite | D．Unless |
When doing your history homework on the Civil War by typing in details to Google, a list of related books will ______ .
| A．come on | B．come up | C．come down | D．come across |
He _______ to go to Tsinghua University to study after graduating from high school, so he is working very hard.
| A．demands | B．defends | C．desires | D．designs |