真核生物中tRNA和5SrRNA的转录由下列哪种酶催化()
A.RNA聚合酶Ⅰ
B.反转录酶
C.RNA聚合酶Ⅱ
D.RNA聚合酶全酶
E.RNA聚合酶Ⅲ
参考答案:E
麻痹性肠梗阻呕吐的特点
A.呕吐物为血性B.呕吐出现晚、呕吐物带粪臭味C.呕吐早、频繁D.呕吐物为带酸臭味的宿食E.呕吐呈溢出性
—If a=4, b=5, what's the answer to the question "a + 2ab +1 =?"
—_______.[ ]
A. Forty-fifth
B. Forty-five
C. Twenty-three
D. One hundred and twenty-one