人们对光的本质的认识,最初是微粒说,它成功地解释了一些光现象,但说明不了光的衍射、干涉和它在水中的速度比在空气中慢等现象,因而产生了波动说,但波动说解释不了光电现象,后来又被认为光是微粒性和波动性的统一的波粒二相说所代替。光的波粒二相性说明
The parcel was a whole week late. How I wish Iair mail instead.
—Could you please have my car ready today? —Sure, the damage is not that serious, so it _____be ready by 5: 00 pm.
If you want to see the chairman of the department, you’d better make an _______ with his secretary first.
The project by the end of 2033,will expand the city’s telephone network to cover 2 000 000 users.
The crazy fans___________ patiently for two hours, and they will wait till the movie star arrives.