在DNA重组中，催化形成重组DNA分子的酶是
A．拓扑异构酶B．DNA连接酶C．解链酶D．DNA聚合酶E．反转录酶
参考答案：B
The doctor telephoned to say that he couldn’t ____ the meeting because he had to ___ a patient.
A．came to; attend to
B．attend; attend
C．join; treat
D．attend on; look after
味连主产地为（）.
