第12题: [单项选择]嘧啶核苷酸从头合成首先合成的化合物是() A. dUMP B. UMP C. dTMP D. TMP E. CMP 参考答案:B 答案解析:嘧啶核苷酸从头合成首先合成UMP,UMP经尿苷激酶和尿苷二磷酸核苷激酶催化,生成UTP,UTP在CTP合成酶催化下从谷氨酰胺获得氨基生成CTP。
第23题: [单项选择]The authority to grant an alternate procedure for oil transfer operations rests with the (). A. nearest Coast Guard office B. Officer-in-Charge,Marine Inspection C. Area Commander D. Captain of the Port 参考答案:D
第25题: [单项选择]When he got out of the managers office, from his facial expression we knew that his proposal must have been (turned down). A. refused B. accepted C. adopted D. denied 参考答案:A 答案解析:refuse“拒绝”。accept“接受”;adopt“采纳”;deny“否定”。本题译文:从经理的办公室出来时,从他脸上的表情我们可以看出他的建议肯定被拒绝了。