--- I don’t know whether they did this ____ or by design. --- Who cares? They have to be punished. 

(2013·辽宁，29)To her joy，Della earned first the trust of her students and then ________ of her colleagues.

It is reported that floods and serious loss of soil and water have _______an ample amount of mud in the Yellow River, making pumping water out of it hard for farmers around.

 Although the living standards of Chinese people have greatly improved, most poor families in China spend      50% of their income on food.

 Last year the number of students who graduated with a driving license reached 200,000，a(n) ________ of 40,000 per year.(2010·江西)