再来3道语法题

woaihenglia

首先祝各位新年快乐哈

The Audubon Society and other conservation groups, concerned over what they have perceived to be the serious threatening of the environment as posed by the policies of the government, are preparing for a major political effort.
(A) have perceived to be the serious threatening of the environment as
(B) perceived as the serious threat to the environment as
(C) perceive being the serious threat to the environment
(D) are perceiving as the serious threatening of the environment（E）
(E) perceive as the serious threat to the environment

这题我问的是这题可以用过去式吗？ perceive这个词是固定搭配是加as吗？


13.On the Great Plains, nineteenth-century settlers used mud and grass to build their homes, doing it without timber and nails.
(A) settlers used mud and grass to build their homes, doing it without
(B) settlers used mud and grass to build their homes, did it without
(C) settlers used mud and grass to build their homes, making them while not having
(D) settlers used mud and grass to build their homes, making do without（D）
(E) settlers’ homes were built of mud and grass, making do without

这题的making do是怎么回事？



14.Intended primarily to stimulate family summer travel, the new airfare, which allows both an adult and a child to fly for the price of one ticket, and also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than fourteen.
(A) and also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than
(B) and also lessens the advance-purchase requirement for family travel to a seven-day minimum from
(C) also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than that of
(D) also lessens the advance-purchase requirement for family travel to a seven-day minimum from（E）
(E) also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than

E对了，为啥加and就错了？




13.On the Great Plains, nineteenth-century settlers used mud and grass to build their homes, doing it without timber and nails.
(A) settlers used mud and grass to build their homes, doing it without
(B) settlers used mud and grass to build their homes, did it without
(C) settlers used mud and grass to build their homes, making them while not having
(D) settlers used mud and grass to build their homes, making do without（D）
(E) settlers’ homes were built of mud and grass, making do without

这题的making do是怎么回事？



14.Intended primarily to stimulate family summer travel, the new airfare, which allows both an adult and a child to fly for the price of one ticket, and also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than fourteen.
(A) and also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than
(B) and also lessens the advance-purchase requirement for family travel to a seven-day minimum from
(C) also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than that of
(D) also lessens the advance-purchase requirement for family travel to a seven-day minimum from（E）
(E) also shortens the advance-purchase requirement for family travel to a minimum of seven days rather than

E对了，为啥加and就错了？