青藏地区的主要自然特征是[ ]
A、干燥地区广，地面植被少
B、地势高，气温低
C、平原广阔，水乡处处
D、黄土深厚，沟壑纵横
答案：B
With respect to closed-end investment companies, generally they:（）
A. buy shares back from investors who want to sell.
B. have the market price of their shares determined by supply and demand.
C. sell additional shares only through the secondary market.
停抽式SG5型动力仪测试载荷为（）。
A、0~80kN
B、O~l00kN
C、0~120kN
D、0~140kN
