1.nonplussed ? ? ? ? ? ? ? ?ADJ

so surprised and confused that you do not know what to do or say 驚呆的；非常困惑的

仿I was completely nonplussed by his sudden disappearance.

2.in a row

1 if sth happens several times in a row,it happens in exactly the same way each time, and nothing different happens in the time between 連續(xù)幾次地

2 if sth happens for several days, etc. in a row,it happens on each of those days 接連幾天（等）地

仿He thinks it's unlikely to have such an accidental two times in a row.

3.Summary

Lockhart thought that Harry was as eager to be famous as him. Therefore,Harry went to school by the magic car to attract other's attention. But in fact, Harry didn't think so.