He tried his best to solve the problem, _____ difficult it was.
| A．however | B．no matter | C．whatever | D．although |
.He must be helping the old man to water the flowers, _____?
| A．is he | B．is’t he | C．must he | D．mustn’t he |
Hearing the dog banking fiercely, away _______
| A．fleeing the thief | B．was fleeing the thief |
| C．the thief was fleeing | D．fled the thief |
John plays basketball well ,_____his favourite sport is badmiton .
| A．so | B．or | C．yet | D．for |
.Either you or one of your students______to attend the meeting that is due tomorrow.
| A．are | B．is | C．have | D．be |
Please do me a favour ---______my friend Mr smith to Youth Theatre at 7:30tonight.
| A．to invite | B．inviting | C．invite | D．invited |