I （） for the bus for the past 20 minutes and still it has not come.

A:wait B:waited C:have waited D:have been waiting

I must get down (to) (write) the composition. (There) is only 20 minutes (left)

A:to B:write C:There D:left

Your dog needs at least 20 minutes of vigorous exercise every day（　）.

A:energetic B:physical C:regular D:free

Your dog needs at least 20 minutes of vigorous exercise every day.

A:energetic B:free C:physical D:regular

Your dog needs at least 20 minutes of (vigorous) exercise every day.

A:energetic B:free C:physical D:regular

One of the most common injuries teenagers and adults experience is a sprained ankle. A sprain occurs when the ligaments(韧带)of a joint are twisted(扭伤) and possibly torn. Ligaments are bands of fibers that hold the bones of a joint in position. A sprain can occur from a sudden twisting at the joint, or a stretching or tearing of the fibers of the ligaments. The injured area usually swells(肿胀) and becomes black and blue. Stepping off the sidewalk at the wrong angle or having one foot land in a hole while walking or running can leave you rolling on the ground in pain with an ankle on fire! If you cannot walk without experiencing intense pain,you must seek medical help. If the pain is manageable,and you can walk,here are three words to help you remember how to treat yourself:
■ Elevate(抬高)
■ Cool
■ Bandage (打绷带 )
As soon as there is injury to that ligament, there will be a certain amount of bleeding under the skin. Once the blood pools around the damaged blood vessels, swelling occurs. The pressure from the swelling results in additional stress and tenderness to the region. In order to reduce the degree of swelling, lie down as soon as possible and keep the ankle elevated so that it is actually higher than your heart. Next,to reduce blood distribution and keep bleeding to a minimum,apply a cold pack. After 20 minutes, take the pack off,wait half an hour and then reapply. This can be done several times a day for a total of three days.
Never leave a cold pack on for more than 20 minutes at a time. Reducing the temperature in that area for an extended period of time signals the body to increase blood flow to raise the body temperature! Therefore,one accidentally triggers more blood distribution to the affected area by leaving a cold pack on for too long! Finally,bandage the ankle. Be careful not to wind it too tightly;doing so can restrict blood flow and cause harm to the entire foot.
Once the initial cold pack is removed,what is to be done

A:Wait 30 minutes and then reapply the ice pack for 20 minutes. B:Begin bandaging the ankle. C:Keep the ankle in a position lower than your heart. D:Wait 20 minutes and then reapply the ice pack for 30 minutes.

Your dog needs at least 20 minutes of {{U}}vigorous {{/U}} exercise every day.

A:energentic B:physical C:regular D:free

Your dog needs at least 20 minutes of vigorous exercise every day．（）

A:physical B:energetic C:regular D:free

There is a drifting mine________in position 21 degrees31 minutes North 124 degrees20 minutes East.

A:report B:reports C:reported D:reporting