题干
I have ______ art teacher and ______ Chinese teacher.
A：a, a
B：an, an
C：an, a
答案(点此获取答案解析）
C
I have ______ art teacher and ______ Chinese teacher.
A：a, a
B：an, an
C：an, a
Rn)，该原子核内的中子数是
