可使甲状腺增大、充血的是
A．老年人B．青壮年C．2岁以内小儿D．3岁以上儿童E．新生儿
参考答案：A
I think this is the most interesting thing _____ has happened to us .
A．that
B．which
C．what
D．who
1个信令复帧包含（）个TDMA帧。
A.32
B.26
C.51
D.52
