I ____________ you an English book yesterday.[ ]
A. buy
B. buying
C. bought
答案:C
People around the country were excited __________ the astronauts came back to the earth safely.
A.unless
B.but
C.until
D.because
乳糜尿中主要含有( )
A.淋巴液B.血液C.蛋白质D.白细胞E.细菌