题目

2018年12月8日，嫦娥四号探月卫星沿地月转移轨道直奔月球，从环月圆轨道上的P点实施变轨进入椭圆轨道,再由近月点Q开始进行动力下降，最后于2018年12月16日成功落月。假设嫦娥四号在环月段圆轨道和椭圆轨道上运动时，只受到月球的万有引力。下列说法正确的是A. 若已知环月段圆轨道的半径、运动周期和引力常量，则可以计算出月球的密度B. 在环月段椭圆轨道上运行周期比在环月段圆轨道上的周期大C. 在环月段圆轨道上经过P点时开动发动机加速才完形填空The White House is an important historical building in the USA. It lies1the country's capital. Many people expect2see the palace with their own eyes.We3six months getting tickets to visit the White House. I was 4with excitement while we were waiting in the White House South Lawns. The first thing5interested me was the colorful flowers and green grass.Everything inside and outside was6kept in the white House. We went7many security checks(安检)8entering the building. In the east hallway9the first floor, I saw the pictures of past presidents on the walls. The10had over 2700 books. The Vermeil Room(金银屋) and China Room（瓷器屋） showed different11We walked upstairs to the State Floor. The East Room, the12in the White House, was the most wonderful in its size and furniture. This is the room where the president usually13the reporters. The Green, Blue and Red Rooms on the same floor got their names because of the 1414of the furniture and walls. These rooms are15having parties for state guests.（1）A.on B.in C.to D.at （2）A.in B.at C.to D.on （3）A.spend B.took C.take D.spent （4）A.full B.covered C.filled D.satisfied （5）A.which B.that C.where D.what （6）A.well B.badly C.quickly D.easily （7）A.past B.across C.through D.away （8）A.until B.whether C.after D.before （9）A.of B.on C.in D.at （10）A.library B.museum C.theater D.hall （11）A.collections B.people C.animals D.flowers （12）A.longer B.smallest C.larger D.brighter （13）A.tells B.meets C.talks D.speaks （14）A.sizes B.materials C.designs D.colors （15）A.made of B.used for C.used as D.regarded as