His father makes a promise to him that he will buy him a computer if he a good score for the entrance examination to college this June.
The number of the students in our school ________ about 3000 and ______ them study hard.
Rather than ______ on a crowded bus, he always prefers _____ a bicycle.
He has devoted most of his time and energy _______ a cure for the disease.
The child asked his mother _______ go out to play tennis.
– Do you know the West Lake in Hangzhou? – Yes, this is the third time that I ____ this beautiful city.