18。The bathyscaphe, a free-moving vessel (designed) for underwater exploration, (consists of) a flotation compartment (with) a observation capsule (attached underneath) it.
答案选D。怎么改呢?(with) a observation 中a应该用an才对吧!
39。(Generally), Abstract Expressionist art is without recognizable images (and does) not (adhere the) Limits of comventional (form).