11. In the temple, there is an ancient scale. For objects weighing less than 1000 grams, the scale shows their correct weight; for objects weighing 1000 grams or more, the scale shows a random number greater than or equal to 1000. Xiao Ming has five items, each weighing less than 1000 grams, which we will denote as $\mathrm{P}$, $\mathrm{Q}$, $\mathrm{R}$, $\mathrm{S}$, and $\mathrm{T}$ for their weights. When these five items are paired and weighed on the scale, the following results are obtained: $Q+S=1200$ (grams), $R+T=2100$ (grams), $Q+T=800$ (grams), $Q+R=900$ (grams), $P+T=700$ (grams). What is the order of the weights of these five items from heaviest to lightest?
【Analysis】From the last three results, it is easy to see that $\mathrm{R}$ is 100 grams heavier than $\mathrm{T}$, and $\mathrm{Q}$ is 100 grams heavier than $\mathrm{P}$. From the second result, we know that $R+T$ is greater than or equal to 1000 grams, while $Q+T$ equals 800 grams, so $\mathrm{R}$ is at least 200 grams heavier than $\mathrm{Q}$. Since $\mathrm{R}$ is 100 grams heavier than $\mathrm{T}$, we currently have $R>T>Q>P$. From the first result, $Q+S$ is greater than or equal to 1000 grams, while $Q+R=900$ grams, so $\mathrm{S}$ is heavier than $\mathrm{R}$. Therefore, from heaviest to lightest, it is $\mathrm{S} 、 \mathrm{R} 、 \mathrm{~T} 、 \mathrm{Q} 、 \mathrm{P}$.