轻型（柔性）直流输电的主要作用包括（）。
A.向偏远地区供电
B.小规模发电厂接入
C.城市配网增容改造
D.长距离大容量输电
参考答案：A, B, C
Schools across China are expected to hire 50,000 college graduates this year as short-term teachers, almost three times the number hired last year, ____ reduce unemployment pressures.
A．help
B．to have helped
C．to help
D．having helped
水肿明显的伤口最好用（）
A.0.9%生理盐水
B.3%高渗盐水
C.0.1%雷佛奴尔溶液
D.优琐溶液
E.10%硝酸银烧灼
