【单选题】Enough sleep is important to health. The amount of sleep 【C1】______ depends on the age of the person and the conditions in which sleep 【C2】______ . The young may need more sleep than the old, but 【C3】...
【简答题】Enough sleep is important to health. The amount of sleep __ 1 ________(need) depends on the age of the person and the conditions in _ 2. ________ sleep takes place. The young may need more sleep than ...