It is becoming more and more difficultto_______the problems of traffic in some big cities of our country.

Sandy’s family can’t afford _______ a new house at present.

你与对方初次见面并听到对方说Niceto meet you 时， 你应该说____________

____ that saw the trade between the two countries reach its highest point.　　

tal cost of this project will be more than________ that of the one last century, which is expected to cost below US ascore billion