下列外加剂中，( )能迅速提高混凝土的凝结硬化速度。

A．木质素磺酸钙

B．FDN

C．728型

D．CaCl₂

What lead to the resistance to treatment of the parasite().

A. The use of antibiotics.

B. People’s negligence.

C. The wrong way of using drugs.

D. The treatment with antibiotics and quinine drugs.