红霉素与林可霉素合用可使
A．不良反应减少
B．血药浓度增高
C．抗菌活性增强
D．产生拮抗作用
E．抗菌谱扩大
参考答案：A
下列关于淀粉和纤维素的叙述，正确的是
A．分子式相同
B．属于同一类物质
C．互为同分异构体
D．化学性质相同
What a pity! The little girl had to drop out of school and _____ the responsibilities that
most parents can take, after her parents passed away in the earthquake. [ ]
A. take on
B. take in
C. take off
D. take after
