脱臼是指（ ）

（a＞b，且a、b都是自然数）

根据上述条件，可以确定（   ）最先完成任务．

增加：在缺词处加一个漏字符号（∧），并在此符号下面写出该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1.每处错误及其修改均仅限一词；2.只允许修改10处，多者（从第11处起）不计分。

Dear Ms Smith,

    I am secretary of the City Student Union (CSU).We were organizing an art exhibition for high school students in city.This will be held on the 9^th of July in the Exhibition Hall of Beihai.More than 1000 painting will be on show, but high school students and teachers from all the eight districts will come to the event.As you are very popularly with us Chinese high school students,we'd like to invite for you to the exhibition.We would be grateful when you could join them that day.Looking forward to hear from you soon.

Yours,

Li Ming

小明学习了燃料的热值后，自己设计一个实验来比较煤油和菜籽油的热值。他实验的装置如图，并每隔1分钟记录了杯中水的温度（见下表）