单选题 If we ______ more free time, we would take the river cruise.
A. has
B. have
C. having
D. had

【正确答案】 D
【答案解析】这个第二条件句中主句的would take要求if从句使用一般过去时，只有选项(D)符合要求。选项(A)和选项(B)是一般现在时，而选项(C)是现在分词。