问题
People are starting to use energy from the sun, wind and water because they cost very________ and will never ________ .
A:do my homework
B:did my homework
C:was doing my homework
D:am doing my homework;
B:did my homework
C:was doing my homework
D:am doing my homework;
正确答案是：
同类题型
______ do you usually go to bed —At six.
When did your school hold the sports meet—Last week. And I _______ the girls’ 400-metre race.
Washington, a state in the US, was named ______one of the greatest American presidents.
I can’t stand the smell of the fruit.–Would you like to have a try It________quite delicious!
They say __________ and mine is on Saturday, when I was chosen to be the host