单项选择题
Construction of the railways helped to develop the national （） of Tanzania and Zambia.
A.economic B.economies C.economics D.economical
单项选择题 Take it（）It is nothing but a joke.
单项选择题 I'm（）to graduate in the next half of the year.
单项选择题 When I came through the customs at the airport, I had to pay（）on a clock I had bought.
