Moreover, the effect is often 20 space motion sickness, headaches, and nausea.
答案：(D) accompanied by
be accompanied by 是「伴隨著、同時出現」，本句指這種效應常伴隨著太空動暈症、頭痛與噁心；varied with（隨…而變）、brought about（引起，主詞須是原因）、transferred from（從…轉移）語意都不合。
accompany 你記得的大概是「陪伴」，腦中畫面是人陪人（My mother accompanied me to the hospital. 我媽媽陪我去醫院）。用於抽象事物時，be accompanied by 的意思是「伴隨著、同時出現」。
空格前為 is often、後接三個並列名詞，可知此處為被動語態加介系詞的結構，主詞 the effect 是承受動作的一方。劍橋詞典對 accompanied by sth 的釋義是「與某事物同時存在或伴隨出現」，全句意為「這種效應常伴隨著太空動暈症、頭痛與噁心」。作答線索在前文 As a result, the astronauts have swollen, puffy faces（因此太空人的臉會變得腫脹浮腫），已說明該效應指的是臉部浮腫，此處補述隨之出現的其他症狀，兩者為並列而非因果。凡是被動語態後接介系詞的題目，判斷步驟相同：先確認主詞是動作的承受者，再檢查各選項所要求的主詞是原因還是結果。
brought about 是「引起、導致」，主詞須是原因；本句主詞 the effect 本身即是結果，方向相反，且原文只是並列描述同時出現的現象，並未主張因果。varied with 是「隨…而變化」，須有可變動的量；transferred from 是「自…移轉」，語意皆不合。另須注意 accompany 為及物動詞，後面直接接受詞，不加 with。
be accompanied by（伴隨著）、accompany sb（陪伴某人，不加 with）、bring about a change（帶來改變）、motion sickness（動暈症）、nausea（噁心）。
Gravity has been at the top of the science agenda since the start of Mars missions. In the earlier days of space travel, scientists tried to overcome the force of gravity so that a rocket could shoot 16 Earth's pull in order to land humans on the moon. Today, they are more interested in how reduced gravity affects the astronauts' 17 condition. Our bodies have evolved to exist within Earth's gravity (1 g), not in the weightlessness of space (0 g) or the microgravity of Mars (0.3 g).
When on Earth, we have more fluids in our lower body because they are pulled down by Earth's gravity. However, with the absence of gravity in the outer space, our body fluids 18 , shifting toward the upper body and the head. As a result, the astronauts have swollen, puffy faces, very much resembling that of the round-headed Charlie Brown in the famous comic strip.
This "Charlie Brown effect" will be more 19 when the astronauts go on their Mars missions, which will take about three years to complete, much longer than missions to the moon. Moreover, the effect is often 20 space motion sickness, headaches, and nausea. Such a syndrome is considered the top health risk for the astronauts, and scientists are still trying to figure out how it may be prevented.