题干
What a(n) ________ it is that Rebecca comes—you can have her for a friend．（ ）
A：ease
B：assistance
C：comfort
D：relief
答案(点此获取答案解析）
C
What a(n) ________ it is that Rebecca comes—you can have her for a friend．（ ）
A：ease
B：assistance
C：comfort
D：relief
的非负整数解是