答案：A。let down:（在紧要关头）抛弃， 不支持。Don’t let me down, I need your support.别瞥下我不管,我需要你的支持。本句意思是：这个年轻人向他的父母承诺：我决不会抛弃你们的。因此只有A 最符合题意。let out :放走，释放。Who let the air out of my tyres?谁放了我轮胎的气？let in 允许进入。He let them in by a side door.他让他们从边门进入。let by 没有这个用法。
Part III Identification
61. The meeting was [interesting] [to] some people, [and] to me it was
A B C
[boring].
D
答案：C。应改为but, 并列句， 表示转折。
62. [Ever since] the world [began], nations [have difficulty] [in keeping]
A B C D
peace with their neighbors.
答案：C。应该为 have had difficulty 。因为ever since 引导句子的时候，从句用过去时，主句要用现在完成时。
63. Mary showed the [customs] officer her passport, [then] John showed
A B
[him] [his one].
C D
答案：D。应改为his，名词性的物主代词。
64. I was just [falling] [sleep] last night [when] I heard a knock [at] the
A B C D
door.
答案：B。应改为asleep, 因为fall 是系动词，后面接表语。
65. She was [angry], went [out], and [slamming] the door [behind] her.
A B C D
答案：C。应改为slammed, 因为句中， went out 和slammed 并列。
66. Bats [are able] [to guide them] by producing sound waves [too high]
A B C
for us [to hear].
D
答案：B。应改为：to guide themselves。
67. The boy denied [to have seen] [anyone] in the building when
A B
