The employment rate has continued to rise in big cities thanks to the efforts of the local governments to increase________. (2011·北京,34)
Radium salts,which have been found to ______ in bones,give rise to bone cancer.
Our teacher insisted that the key words worth paying attention _______ before class.
With some technical problems to be solved, it may be a while _______ the system is put into use.
That is the only way we can imagine _______ the overuse of water in students’ bathrooms.
A great deal of advanced science and technology has been _______ since China carried out the reform and opening policy.