GWD28里的两道语法题，求求大家了，太困惑了

1.In the Louisiana Purchase of 1803, the United States acquired 828,000 square miles for about four cents an acre, which more than doubled the country’s size and that brought its western border within reach of the Pacific Ocean.

1. In the Louisiana Purchase of 1803, the United States acquired 828,000 square miles for about four cents an acre, which more than doubled the country’s size and that brought
2. For about four cents an acre the United States acquired, in the Louisiana Purchase of 1803, 828,000 square miles, more than doubling the country’s size and it brought
3. With the Louisiana Purchase in 1803, the United States acquired 828,000 square miles for about four cents an acre, more than doubling its size and bringing
4. The United States, in the Louisiana Purchase of 1803, for about four cents an acre, acquired 828,000 square miles, more than doubling the country’s size, bringing
5. Acquiring 828,000 square miles in the Louisiana Purchase of 1803, the United States bought it for about four cents an acre, more than doubling the country’s size and bringing

答案C，我觉得是E

2.

According to entomologists, single locusts are quiet creatures, but when locusts are placed with others of their species, they become excited, change color, vibrate, and even hum.

1. when locusts are placed with others of their species,
2. when placing them with others of their species, then
3. locusts, when placed with others of their species,
4. placing them with others of their species,
5. placed with others of their species, then

答案是A，我觉得是E

各路高人帮帮忙，真得非常非常困惑！

According to entomologists, single locusts are quiet creatures, but when locusts are placed with others of their species, they become excited, change color, vibrate, and even hum.

1. when locusts are placed with others of their species,
2. when placing them with others of their species, then
3. locusts, when placed with others of their species,
4. placing them with others of their species,
5. placed with others of their species, then

答案是A，我觉得是E

各路高人帮帮忙，真得非常非常困惑！

1 E中的it指什么？ Louisiana Purchase虽然是单数 但是逻辑上不合理的 你不能说美国购买了“路易斯安那的购买”

2 when是必须要有的，locusts倒是可以省略 then也是不需要的

1. E中价格不能doubling size； it没指代

2. E中but后面的分词没有平行并列对象