阅读下面的文言文，完成下列问题。

    罗亨信，字用实，东莞人。永乐二年进士。仁宗嗣位，始召入为御史。监通州仓储， 巡按畿内。

    英宗即位之三月，擢右佥都御史，练兵平凉、西宁。正统二年，蒋贵讨阿台、朵儿只伯，亨信参其军务。至鱼儿海，贵等以刍饷不继，留十日引还。亨信让之曰：“公等受国厚恩，敢临敌退缩耶？死法孰与死敌？”贵不从。亨信上章言贵逗遛状。帝以其章示监督尚书王骥等。明年进兵，大破之。亨信以参赞功，进秩一等。

    父丧归葬。还朝，改命巡抚宣府、大同。参将石亨请简大同民三之一为军，亨信奏止之。十年进右副都御史，巡抚如故。时遣官度二镇军田，一军八十亩外，悉征税五升。亨信言：“文皇帝时，诏边军尽力垦田，毋征税，陛下复申命之，今奈何忽为此举？塞上诸军，防边劳苦，无他生业，惟事田作。每岁自冬徂春迎送瓦剌使臣三月始得就田七月又复刈草八月以后修治关塞计一岁中曾无休暇。况边地硗瘠，霜早收薄，若更征税，则民不复耕，必致窜逸。计臣但务积粟，不知人心不固，虽有粟，将谁与守？”帝纳其言而止。

    初，亨信尝奏言：“也先专候衅端，以图入寇。宜预于直北要害，增置城卫为备。不然，恐贻大患。”兵部议，寝不行。及土木之变，人情汹惧。有议弃宣府城者，官吏军民纷然争出。亨信仗剑坐城下，令曰：“出城者斩！”又誓诸将为朝廷死守，人心始定。也先挟上皇至城南，传命启门。亨信登城语曰：“奉命守城，不敢擅启。”也先逡巡引去。赤城、雕鹗、怀来、永宁、保安诸守将弃城遁，并按其罪。

    当是时，车驾既北，寇骑日薄城下，关门左右皆战场。亨信与总兵杨洪以孤城当其冲，外御强寇，内屏京师。洪既入卫，又与朱谦共守，劳绩甚著。景帝即位，进左副都御史。明年，年七十有四矣，乞致仕。许之。归八年，卒于家。

（节选自《明史•罗亨信传》）

    When it comes to the letter grade on your test or homework, you might notice that there is no letter E. Have you ever thought about why that is so?

    In the A, B, C, D and F grading system, the first four letters are typically considered passing grades. An F in this system simply stands for“fail”.The word“fail”happens to start with the letter F, which seems to leave out the letter E. The fact”．Some schools have U grade for“unsatisfactory”,or I grade for “incomplete”.

    Even with all this said, we should also point out that E grade actually has been used pretty commonly throughout the history of letter grades in the US.

    The first college in the US to use a letter grading system like the ones we use today is Mount Holyoke College. In 1897, they began to use the following grading scale:

A: 95-100%(excellent)       B: 85-94%(good)      C: 76-84%(fair)

D: 75%(barely passed)       E: below 75%(failed)

    We can see the inclusion of E instead of F.

    Gradually,the letter grading system became more popular throughout the US. However, many schools decided to drop the E grade and go straight to F.There is no evidence(证据) to really support this, but one possible explanation is that teachers were worried that some students and parents might mistake E for “excellent”.

    Why do we have letter grades? Well, part of the reason is that they made grading simpler during a time of great change for schools. As the 20th century began,growing cities and an increase in immigration led to larger school classrooms. Most teachers at that time thought this new letter grading system was an easy, fair and clear way to grade students.

    Today, more and more people argue that letter grades don't fully reflect(反映) student learning. However，as teachers try to improve grading methods, many parents continue to favor the letter grades they got as kids, they are familiar(熟悉) and easy for parents to understand. So while they might not be perfect, the letter grades probably aren't going away any time soon.

读课文《和时间赛跑》，根据意思写词语。

①使心情安适。____

②悲伤，悲痛。____

③受到的启发或益处很大。受益非浅，收获很大。____