阅读短文，然后从短文括号中所给词的适当形式填空。

Climbing the highest mountains in the world is not an  小题1:  (easily) job．You have to fight bad weather，illness and fear．But Jordan Romero，a thirteen-year-old boy from America，will climb小题2:(Asia) highest mountain，Mount Qomolangma．He will set out this month．小题3: (He)parents and helpers will climb with him．He plans to take  小题4: (second)months for his climb．“I’m ready．But if I don’t reach the top 小题5: (successful)，I’ll try next time，”he said. Jordan has already climbed the highest mountains of six other continents(洲)．If he 小题6:  (get)to the top this time，he will become the youngest person to climb the world’s highest mountain．

为制定某地区人群原发性高血压的社区综合防治方案，拟对某地区某时点原发性高血压的患病情况进行调查，这类研究是（）。

A.描述性研究

B.分析性研究

C.病例对照研究

D.队列研究

E.流行病学实验