—____ I swim here?

—I’m sorry. Children ____ swim alone here..

A．Must, can’t

B．May, must

C．Can, mustn’t

D．Can’t, can

血管外破坏红细胞的主要场所是

A．肾和肝

B．脾和肝

C．胸腺和骨髓

D．肺

E．淋巴结