A.Fe.
B.Na.
C.Mg.
D.Cu.

A.Na3AlF6.
B.Al(OH)3.
C.KAl(SO4)2.12H2O.
D.Al2(SO4)3.

A.Etan.
B.Etanol.
C.Etilen.
D.Metan.

A.\(\left( { - 1;1} \right)\)
B.\(\left( { - \infty ; - 1} \right) \cup \left( {1; + \infty } \right)\)
C.\(\left[ { - \dfrac{1}{2};1} \right)\)
D.\(\left( { - 1; - \dfrac{1}{2}} \right)\)

A.2020
B.4037
C.2019
D.4038

A.\(1 < m \le 3\)
B.\(1 < m \le 5\)
C.\(1 \le m \le 5\)
D.\(1 \le m \le 3\)

A.6
B.5
C.9
D.4

A.
B.4
C.Vô số
D.3

A.2
B.6
C.Vô số
D.1

A.They make apples' colors brighter than those of other fruits.
B.They are less important than beta carotene and B vitamins.
C.They help prevent the risks of several health problems.
D.They may lead to the feeling of being bloated and uncomfortable.