蔬菜、水果中有害化学物质的污染包括（）。
A.农药
B.工业废水
C.硝酸盐与亚硝酸盐
D.肠道致病菌
E.寄生虫卵
参考答案：A, B
He _________ long curly hair but my hair ______ very straight and short.
A．used to be, used to have
B．used to have , used to be
C．used to be, used to be
D．used to have , used to have
finite clause
