Listen! The bird ________ now.[ ]
A. sing
B. is singing
C. will sing
答案：B
下列现象或事实能用同一原理解释的是 [ ]
A．乙烯能使Br2水和KMnO4溶液褪色
B．二氧化硫、氯气都会使品红溶液褪色
C．饱和(NH4)2SO4溶液和饱和CuSO4溶液都能使蛋白质溶液产生沉淀
D．常温下，铁片和铝片放入浓硫酸中都能出现钝化现象
—How old was Langlang?
—He was born ______ May 1st,1982. [ ]
A. in
B. at
C. on
D. for
