列选项中能保护蔬菜中的营养素的方法为()。
A.洗后蔬菜放置时间过长
B.旺火急炒
C.炒煮的时间过长
D.长时间浸泡
参考答案:B
To keep healthy, most retired old people _____ jogging as a regular form of exercise.
A.take up
B.make up
C.carry out
D.hold out
Foam-type portable fire extinguishers are most useful in combating fires involving().
A.solid materials such as wood or bales of fiber
B.flammable liquids
C.electrical equipment
D.metallic solids