By the time he was ten,Edison______experiments in chemistry.
| A．had already done | B．already had done |
| C．was already doing | D．already did |
. Alice is a character in the novel the movie is adapted by Tim Burton.
| A．in which | B．from which | C．for which | D．by which |
. The government doesn’t know how to deal with the dangerous situation all the public are aware of at present.
| A．where | B．which | C．when | D．who |
. Don't bother Tom, he is with the experiment on water molecules in the lab.
| A．focused | B．fixed | C．occupied | D．concentrated |
It’s____ comfort to know that so many people are donating money and food to the people in need.
| A．/, the | B．a, the | C．a, / | D．/, a |
_________ the project in time, the workers were working at weekends.
| A．Completing | B．Having completed | C．To have completed | D．To complete |