In spite of the great difficulties, Helen Keller ______ studying and finally succeeded.
| A．stuck to | B．kept up with | C．kept on | D．insisted on |
With summer coming on, the weather gets hot _________.
| A．day after day | B．day and night |
| C．day in and day out | D．day by day |
In Switzerland, six miles west of Geneva,___________ a collection of laboratory buildings.
| A．lie | B．are lying | C．lies | D．lays |
America was____________ was first called" India" by Columbus
| A．that | B．where | C．what | D．the place |
To everybody's surprise, the fashionable young lady ___________ to be a thief.
A．found out B．proved out C, put out D．turned out
Collecting stamps as a hobby___________ increasingly popular during the past fifty years.
| A．becomes | B．became | C．has become | D．had become |