10. Tom had to______ the invitation to the party last weekend because he was too busy.
A
turn in
B
turn down
C
turn over
D
turn to
turn in上交；turn down 拒绝；turn over 翻转；turn to 转向，求助于（后加人）。故选项B符合答案。
根据下文because he was too busy,因为他太忙了，所以不得不拒绝上周聚会的邀请。
常见短语含义记忆不准致错。