Belgian Citizen applying for visa PRC from Embassy in Dushanbe Tajikistan

Greetings Sir or Madam

I am a Belgian national, residing in Moscow Russian Federation and working in Dushanbe Tajikistan

I am invited to speak at a conference in Shanghai at the end of this month and will apply for a one week entry permit at your embassy in Dushanbe next week Tuesday. I shall be visiting colleagues academics over the weekend in Hong Kong, so my question is : Do I need single entry one to the PRC or double ?

Thank you for taking the time to answer my question