________ hard you try，it is difficult to lose weight without cutting down the amount you eat.(2012·湖南)

(2010·福建)The girl had hardly rung the bell ________ the door was opened suddenly，and her friend rushed out to greet her.

(2010·新课标全国)Mary made coffee ________ her guests were finishing their meal.

(2011·四川)As is reported，it is 100 years ________ Qinghua University was founded.

I'm sorry you've been waiting so long，but it'll still be some time ________ Brian gets back.(2008·北京)

He had no sooner finished his speech________ the students started cheering.(2011·辽宁)

He smiled politely ________ Mary apologized for her drunken friends.(2012·山东)

—Did you return Fred's call?
—I didn't need to ________ I'll see him tomorrow.

Leave your key with your neighbor ________ you lock yourself out one day.(2012·辽宁)

A number of high buildings have arisen ________ there was nothing a year ago but ruins.(2012·山东)