It's quite warm here; we ________ turn the heating on yet．

A．couldn't

B．mustn't

C．needn't

D．wouldn't

I wish to thank Professor Smith, without ________ help I would never have got this far．

A．who

B．whose

C．whom

D．which

Only after Mary read her composition the second time ________ the spelling mistake．

A．did she notice

B．she noticed

C．does she notice

D．she has noticed

The dog may be a good companion for the old．________, the need to take it for walk

s may be a disadvantage．

A．Besides．

B．However

C．Therefore

D．Instead．

You were working too hard．You'd better keep a ________ between work and relaxation．

A．promise

B．lead

C．balance

D．diary

The letters for the boss ________ on his desk but he didn't read them until three later．

A．were put

B．was put

C．put

D．has put

After school we went to the reading-room to do some reading, only to be told that it ________．

A．was decorated

B．had decorated

C．had been decorating

D．was being decorated

Queen Elizabeth Ⅱis often to be richest woman in the world．________, her personal wealth seems rather small．

A．Besides

B．Otherwise

C．However

D．Altogether

Walmart, which is one of the largest American supermarket chains, ________ some of its store open 24 hours on Mondays through Saturdays．

A．keeps

B．keep

C．have kept

D．had kept

Grace doesn't want to move to New York because she thinks if she ________ there, she wouldn't be able to see her parents very often．

A．lives

B．would live

C．having asked

D．were live