Ｉstill remember the day when I said goodbye to my family, ________on the plane and started my journey to London.
| A．to step | B．stepping | C．stepped | D．having stepped |
There is no doubt，in my opinion， ________matters is not the speed，but the quality of the product.
| A．that | B．which | C．what that | D．that what |
Maybe all Americans realize that______ they expect to be next president will face lots of problems.
| A．no matter who | B．whoever |
| C．whomever | D．no matter whom |
It was only when I read this story for a second time ________to appreciate its beauty.
| A．that did I begin | B．had I begun | C．then I began | D．that I began |
Everybody showed great respect to the old doctor, who devoted everything he had to _____ the poor conditions of the local hospital.
| A．improving | B．improve | C．improved | D．being improved |