“$xy>0$”是“$\left|x+y\right|=\left|x\right|+\left|y\right|$”的（   ）

    It's summer holidays. For Jacob, it means having a lot of free time to play with  ____ (he) friends. Usually, he isn't so excited about it, ____ (连词) this summer is different. This summer, he is going to see Justin Timberlake — one of his favourite singers

    Jacob got four tickets to Justin Timberlake's concert after he ____（win) an online singing completion （比赛） ____. (see) Justin Timberlake is one of his dreams (梦想), so it will something he will never forget.

    The biggest problem he had was  trying ____(choose) just three friends to go with him. He ____ (wish) that all his friends could go. He asked his mother ____(介词) help. She told him to choose people who also liked Justin Timberlake. Jacob thought it was ____ (冠词) good idea, so he chose three friends who liked Justin Timberlake as much as he did. He felt sorry for not____(take) his best friend Andrew, but he knew that Andrew didn't like Justin Timberlake' s music that much. Jacob's three friends were all very excited when he ____ (tell) them the good news.

    Now the concert is just a week away and Jacob can't wait any longer.

几内亚位于非洲西部，首都科纳克里是西部非洲最大的港口。该国矿产资源丰富，其中铝土矿储量占世界总储量的三分之一，且品位高，易于开采。西非的三条主要河流——尼日尔河、塞内加尔河和冈比亚河均发源于其中部的富塔贾隆高原，因而有“西非水塔”之称。我国的炼铝工业占世界的40%，而铝土矿资源仅占世界的3%左右。近年来，我国企业在几内亚投资发展铝土矿开采和加工工业。