??内容:
??John’s score on the test is the highest in the class;____. ??选项:
?? a、he should study last night
?? b、he should have studied last night ?? c、he must have studied last night ?? d、he must had to study last night ?? ?? ?? ??
??题号:20题型:（请在以下几个选项中选择唯一正确答案）本题分数:5 ??内容:
??The Kettle drum produces different tones depending on whether____with sticks that have felt or sponge heads. ??选项:
?? a、.to strike ?? b、when struck ?? c、it is struck ?? d、striking it ??