孟德尔在豌豆杂交实验中,发现问题和验证假说所采用的实验方法依次是()
A.自交、杂交和测交
B.测交、自交和杂交
C.杂交、自交和测交
D.杂交、测交和自交
参考答案:C
They _____ hamburgers and milk when they have afternoon tea.[ ]
A. eat
B. drink
C. likes
D. have
当拉远载波用10KM-1.25G-1310nm单模光模块时,载波接收光纤最小可用光功率为()。
A.-12dBm
B.-12dBm
C.-16dBm
D.-20dBm~-26dBm