1. [单选题]Mr. Wang and his son, both looking very happy, ______ taking a walk in the park.
A. are
B. is
C. has
D. have
2. [单选题]In this article, you are not told that Billy Joel is a ______.
A. singer
B. composer
C. performer
D. guitar player
3. [单选题]先进社会意识之所以(the reason that)能对社会的发展起促进作用，是因为（ ）
A. 它正确反映了社会发展规律
B. 它是社会存在的反映
C. 它具有相对独立性(relative independence)
D. 它具有历史继承性(historical inheritance)
