Among the following, the correct statement(s) is(are)

• Correct answer
  A

  $Al{\left(C{H}_3\right)}_3$ has the three-centre two-electron bonds in its dimeric structure
• B

  $AlC{l}_3$ has the three-centre two-electron bonds in its dimeric structure
• Correct answer
  C

  $B{H}_3$ has the three-centre two-electron bonds in its dimeric structure
• Correct answer
  D

  The Lewis acidity of $BC{l}_3$ is greater than that of $AlC{l}_3$

Hence, the correct answer is options: 'A', 'C', 'D'.