Mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the following questions.

Three _______subjecs in the GCSE examination at the end of this school year are Math, Literature and English.

A. optional

B. main

C. core 

D. academic

Tính giá trị biểu thức:

a,  15 . { 32 : [ 6 - 5 + 5 ( 9 : 3 ) ] + 3 } - 2018 0

b,  25 . { 2 7 : [ 12 - 4 + 2 2 . 16 : 2 3 ] - 2 4 }

c,  2019 . { 101 - 1000 : [ 2 2 . 2 3 + 5 6 : 5 3 - 6 2 : 11 - 2018 0 ] }

Cu(Z=29) có cấu hình electron nguyên tử là:

A.   [Ar]4s²3d⁹

B.   [Ar]3d⁹4s²

C.   [Ar]4s¹3d¹⁰

D.   [Ar]3d¹⁰4s¹