问题
选择题
People around the country were excited __________ the astronauts came back to the earth safely.
A．unless
B．but
C．until
D．because
答案
答案：D
题目分析：考查连词。A. unless除非； B. but但是；C. until直到；D. because因为。句意：全国各地的人们都很激动，因为宇航员安全地返回地球。故D正确。