My Life at Renda I learned very quickly that being a teaching assistant （TA）at the University of Iowa would be different from being a teacher at Renmin University._____（46）Eyes staring，mouths open，students examined my big nose，while I was writing my name on the blackboard.At Iowa，when my first classes began，half of my students still hadn’t arrived.When everyone finally found a seat，ringing cellphones and loud yawns （哈欠）interrupted my opening remarks.It is not that American students were disrespectful._____（47）They were，however，far more skeptical than the students I had at Renda.The truth is I couldn’t fault them for their skepticism.Undergraduates at large US universities -especially freshmen and sophomores -often have several classes a semester handled by TAs.In some cases，the TA sets the course content._____（48）Most have good intentions，but very few are as effective as professors.Every teacher has to confront obstacles to learning -no matter what the culture.Students who talk during lectures，students who cheat，students who question the grade they get for a paper or project -dealing with these is all part of the job._____（49）The difference，I think，is that in the US I had to swallow more of my pride._____（50）I had a responsibility to teach them，of course，but I had to do so indirectly -as a guide who himself had a few things to learn from the students.

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