Paper money was in___use in China when Marco Polo visited the country in___thirteenth century.
I think Tom will _______ a good monitor, so I’m going to vote for him.
I am trying to be the kind of boss that the workers will .
—Watch!—I ____ but ____ I ____ anything unusual.watched; have watched B.have watched; am not seeingC.was watching; wasn’t seeing D.am watching; don’t see
—What field will your son go into after graduation from Nanjing University?—I’m not quite certain, but he ____ a good teacher of English.
The factory had to______ a number of employees because of economic decline in the country.