Ireland's entry into ____ in 1973 was a great boon to the nation's economy.
A. the Missouri Compromise
B. The Canadian Broadcasting Corporation
C. the Potato Famine
D. Greater London
E. the European Communities
F. Heptarchy
G. citizenship
H. Inner London
I. the Canberra Pact
J. nonstatus
K. The British Privy Council
L. status
【正确答案】：E