英语高手进来做定语从句 急 1 every living thing haswhat scientists called

英语高手进来做定语从句 急
1 every living thing haswhat scientists called a biological clock_____controls behavior.
A who B that C whom D this
2 early morning is good time to eat for_____try to lose weight.
A those who B who C those D whoever
3 parts of the earth ____were once under water are now completely dry.
A those B where C/ D that