质检员检测出某市场的白菜中铅、铜等重金属含量超标。这里提到的铅、铜应理解为[ ]
A.原子
B.元素
C.分子
D.单质
答案:B
阅读短文,判断正(√)误(×)。
Jim is an English boy. He is from England. He's 13. He is a new student in our class. Today he is in a
yellow coat. The man in black is his father. He is 40. The woman in white is his mother. She is thirty-six.
His parents are both teachers. Jim has a sister, Jane. She is 15. She is in a green skirt today. She is a student
too. Jim has a happy family.
( ) 1. Jim is 13.
( ) 2. His mother is thirty-seven.
( ) 3. His father is a doctor.
( ) 4. Jim has a sister, Jane.
( ) 5. Jim has a happy family
下列不属于取水工程或者设施的是:()
A.人工河道
B.水井
C.水电站
D.水库