1. Having a trip abroad is certainly good for the old couple, but it remains _____whether they will enjoy it.

　　A. to see B. to be seen C. seeing D. seen

　　【答案】B。本题考查固定用法。It remains to be seen尚待分晓。对于这对老夫妇来说去国外旅游是好事情，但是还得看到底他们喜不喜欢。首先it(老夫妇去旅游这件事)还有待于观察，表将来用不定式。这件事情是被观察，因此选被动。综上选B。

　　2. The purpose of new technologies is to make life easier, _______ it more difficult.

　　A. not make B. not to make C. not making D. do not make

　　【答案】B。新技术的目的是让生活变得更容易，而不是变得更难。不定式作表语。

　　3. One can go a long way after one is _________.

　　A. tireB. tiring C. tired D. to be tired

　　【答案】C。一个人累了之后还能走很远。

　　4. The pilot asked all the passengers on board to remain ________ as the plane was making a landing.

　　A. seatB. seating C. seated D. to be seating

　　【答案】C 飞行员要求飞机起飞时，所有的乘客在座位上坐好。

　　5. He is _______ about why other lions are running away, until an old lion tells him that hunters are coming.

　　A. confused B. confusing C. being confused D. to be confused

　　【答案】A。他感到困惑confused 固定用法。