16. Liu came _____ first by two seconds, breaking _______ record set by Li last year.
A. the ; / B. /; the C. the; a D. /; /
17. I was enjoying my dessert and talking to my American friend Janice at the table _____ I noticed people
staring at us.
A. until B. as C. when D. while
18. _____ they may get injured, parents won’t let their children ____ in the street.
A. Thinking; play B. Thinking; to play C. Think; playing D. To think; play