题干
“Show me your ticket, ________ I won't let you in.”the guard(保安) said angrily.
A：so
B：or
C：but
D：and
答案(点此获取答案解析）
B
“Show me your ticket, ________ I won't let you in.”the guard(保安) said angrily.
A：so
B：or
C：but
D：and
和 
分别表示两种不同元素的原子，那么其中表示混合物（ ）
