The cheaper FNDs fluoresce roughly as well as those produced with an electron beam.此种廉价FND所发的荧光与用电子束生产的FND所发荧光大致相同.The radar beam can track a number of targets almost simultaneously.雷达波几乎可以同时追着多个目标.A high quality beam ha...
这些纸用来封住墙壁和屋顶的洞。The paper was used for sealing up holes in walls and roofs.石料开始被用作盖屋顶的材料。Stone began to be used as a roofing material.我们从屋顶的小洞能看见星星。We could see the stars through an opening in the roof....
Avoiding mosquito bites is easier said than done.防蚊叮咬好说难做。Tick bites can cause Lyme disease.被蜱叮咬会引发莱姆病。This cream contains a mild analgesic to soothe stings and bites.这种乳膏含有一种性能平和的止痛剂,能缓解被螫咬后的疼痛....