51. --- Who is at the _____ of all this trouble.
--- I don’t know.
| A．base | B．bottom | C．reason | D．Cause |
The young couple, who returned my lost wallet, left ______I could ask for their names．
| A．while | B．before | C．after | D．since |
It’s standard practice for senior 3 students like us ________ only 3 day off during our National Day holiday．
| A．having | B．had | C．to have | D．have |
He _______after a few day’s treatment in hospital．
| A．picked up | B．made up | C．took up | D．looked up |
One way to understand thousands of new words is to gain _____good knowledge of basic word formation
| A．/ | B．the | C．a | D．one |
The newly-built tower, _______beyond imagination, is called “ The First Tower in Asia”
| A．eighty-five feet as tall as |
| B．as eighty-five feet tall as |
| C．as tall eighty-five feet as |
| D．as tall as eighty-five feet |