中国电信目前有天翼、号码百事通、商务领航三款套餐体系。
参考答案：错
The great invention he made ___ of great benefit to the whole world.[ ]
A. is proved
B. has proved
C. has been proved
D. is proved to be
尿布性皮炎患儿用灯光照射时，灯泡距臀部患处约为()
A．25cm
B．30cm
C．35cm
D．40cm
E．45cm
