(届北京市海淀区高三下学期期中练习英语试卷)You cannot take back your words ______ they are out of your mouth.
He is the most suitable person _______the task.
_________, the experiment is sure to succeed.
The cost of buying a house in Beijing is higher than ______in Luoyang。
.There are over 58000 rocky objects in _______space,about 900 of which could fall down onto ______earth。
-----Did you enjoy your trip to the town? -----_________. We had driven more than 3 hours before we found the right way.