Can you come to have dinner with me this evening—I’m afraid not. I _______ take care of my grandmother. She is ill.

Lei Feng for many years, but his spirit is still encouraging us.

给下面语句排序，衔接恰当的一项是（ ）①因为较弱的电磁辐射，也会对人的神经系统与心血管系统产生一定的干扰。②人的大脑和神经会产生微弱的电磁波，当周围电器发出比它强数百万倍的电磁波时，人的神经活动就会受到严重干扰。③即使在不太强的电磁波环境中工作和生活，人也会受到影响。④如果长时间处于这种强电磁波的环境中，人会出现头痛，注意力不集中、嗜睡等症状，强电磁辐射会使心血管疾病加重、神经系统功能失调。

______ recent report stated that the number of Spanish speakers in the U.S. would be higher than the number of English speakers by ____ year 2090.

If _____ carefully, the experiment will be successful.