下列表示物质的图或式正确的是（ ） A．氮气的电子式 B．Mg2+的结构示意图

Mr. Smith has had a cast applied to his arm as an outpatient in the emergency room. Which of the following home care instructions should the nurse advice for his cast care

A. Use a ruler to reach inside and scratch under the cast.
B. Apply a heating pad to the arm for 24 hours after the injury.
C. Use powder on the skin around the cast.
D. Smell the cast for foul odors.

五四运动所具有的崭新特点有反帝反封建的彻底性、（）、促进马克思主义的传播并于工人运动相结合

下列《三国演义》的情节中，与诸葛亮有关的有（）

①三顾茅庐

②空城计

③桃园三结义

④三气周瑜

⑤赤壁之战

⑥隆中对策

A.①②③④⑤⑥

B.①②④⑤⑥

C.②③⑤⑥

D.①②③⑤⑥

送风管路上设置静压箱的作用是（）。