【单选题】A beautiful bike _______ him by his classmates. [ ]
【判断题】Lauren was sent to ballet because her parents had no time to take care of her.
【单选题】模拟小实验:(如图准备装置)在两只烧瓶里分别充满CO2和空气,塞紧带有温度计和胶头滴管的橡皮塞。再把两只烧瓶放在红外线下照射,观察温度升高的情况。结论:两瓶在相同光线照射下,装CO2的温度较邻瓶高,最大可达4℃。据此完成下列各题。 大气中二氧化碳增多的主要原因是() ①大量燃烧矿物能源 ②火山喷发 ③过度发展核电 ④过度砍伐森林
【单选题】It is suggested that a doctor _____ immediately. [ ]
【单选题】It was essential that the application forms _____ back before the deadline ( 截止日期 ).
【单选题】Suppose the exchange rate of the U.S. dollar was 1.50 British pounds = $1.00 (U.S.) on Wednesday, and on the following Monday the exchange rate was $.75 (U.S.) = 1.00 British pound. Which of the follo...
A.
The U.S. dollar appreciated against the British pound.
B.
The British pound appreciated against the U.S. dollar.
C.
The U.S. dollar depreciated against the British pound.
D.
Both answers B and C are correct.
【简答题】羰基(>C=O),碳-碳双键(>C=C 打浆和加填均能增加纸页的白度。 在纸页内光的散射越厉害,透过纸页的光量就越少,纸的不透明度就越大。