参考答案:He is serious enough to think twice about everything.
系统解析:
这里是说客观事实用一般现在时, 表示足够怎样去做某事用adj/adv+enough+to do sth, 这里是形容词serious认真的, 主语he 三单, 故is, 对所有事三思而后行, 也就是对所有的事想第二次, 故think twice about everything. 故答案是He is serious enough to think twice about everything.
2
为什么不参加校足球队的选拔呢?
____ .
参考答案:Why not try out for the school football team?
系统解析:
这里是提出建议, 表示为什么不做某事用why not do sth? 参加...选拔try out for, for是介词后加名词the school football team, 故答案是Why not try out for the school football team?