Tom has _____ good knowledge of English and this will improve his chance of finding _____ proper job.

A．a; the

B．a; a

C．/; a

D．/; the

肺炎双球菌肺炎首选抗生素是

A．链霉素
B．红霉素
C．庆大霉素
D．青霉素
E．氨苄青霉素