11.答案D

　　【解析】beneath和under為介詞，后面必需接名詞。down向下地，副詞。below在下方地，副詞，符合句意。

　　12.答案A

　　【解析】close與介詞to連用，意為近的。其他介詞不與close搭配。

　　13.答案D

　　【解析】horror恐懼;trust信任;pleasure愉快;relief(痛苦、憂慮)解除。to one�餾 relief意為讓某人松了一口氣，最符合句意。

　　14.答案B

　　【解析】surround包圍;circle盤旋;observe觀察;view認為。此處選擇circle，最符合句意。

　　15.答案B

　　【解析】be familiar with為固定搭配，意為熟悉，排除其他選項。

　　16.答案C

　　【解析】本句意為危險還沒過去，與前句形成轉折關系。選項中then表順承，therefore表結果，but表轉折，moreover表遞進。

　　17.答案A

　　【解析】根據句意推斷，空格處所填詞應與when he had做同位語，故moment符合句意。movement運動，idea想法，affair事件。

　　18.答案D

　　【解析】following…這個分詞的邏輯主語應為the man，本句意思應為，這個人遵照指令，駕駛飛機朝機場飛去。impression意為印象，information消息，inspections視察，instructions指令。

　　19.答案A

　　【解析】as當……的時候，符合句意。unless除非。while當……時候，它引導的從句動作時間比as引導從句動作的時間要長。So因此，表結果，不符合句意。

　　20.答案C

　　【解析】本句意為：飛機沿著跑道滑行了很長一段距離后，安全地停下來了。move along是沿著……移動的意思。around在……周圍，over在……之上，above在……上方。只有along符合句意。

　　二、　Space is a dangerous place, not only because of meteors(流星) but also because of rays from the sun and other stars.

　　The atmosphere again acts __1__ our protective blanket on __2__ .

　　Light gets through, and this is essential __3__ plants to make the food which we __4__ .

　　Heat, __5__ , makes our environments tolerable and some ultraviolet rays(紫外線的) penetrate the __6__ .

　　Cosmic(宇宙的) rays of various kinds come __7__ the air from outer space,

　　but __8__ quantities of radiation from the sun are screened off.

　　__9__ men leave the atmosphere they are __10__ to this radiation;

　　__11__ their spacesuits or the walls of their spacecraft, if they are inside,

　　__12__ prevent a lot of radiation damage.

　　Radiation is the greatest known danger to explorers in __13__ .

　　Doses of radiation are measured in __14__ called“rems (雷目)”.

　　We all __15__ radiation here on earth from the sun, from cosmic rays and from radioactive minerals.

　　The“ __16__”dose of radiation that we receive each year is about two millirems; it __17__ according toswheresyou live, and this is a very rough estimate.