21. Don’t give up halfway, Andy. You’ll succeed ________ if you keep on working
like this.
A. in return B. on time C. by the time D. in time
22. Along with the letter was his promise _____ he would visit me this coming May Day.
A. that B. which C. what D. whether
23. The government has to close those small factories to prevent the water of the river___.
A. from polluting B. polluted C. polluting D. being polluted
24. Before building a house, you will have to ______ the government’s permission.
A. get from B. hear from C. ask for D. go for
