题目

 On Sundays there were a lot of children playing in the park, _______ parents were seated together joking.     A. their               B. whose      C. which               D. that 答案：B向日葵的花盘总是向着太阳，这说明生物具有什么特征？（　　）A．新陈代谢B．繁殖能力C．应激性D．生长现象