单选题According to the passage, all the following are easier to synthesize EXCEPT ______
单选题These data will be of considerable use for identifying and analyzing environmental degradation, and Uthan/U crafting workable solutions.
单选题Most comets have two kinds of tails, one made up of dust, ________made up of electrically charged particles called plasma.
单选题Donkeys and camels are still widely used in some parts of the world as beasts of______.
单选题______ famous queens in the history of England: Elizabeth I and Victoria.
单选题It has been estimated that only 21 percent of______world's land surface can be cultivated and that only 7.6 percent is actually under______cultivation. A．/.../ B．the...the C．/...the D．the.../
单选题Everything，including the clothes in the closets，______stolen from the apartment.
单选题{{U}}In spite of{{/U}} relatively costly, the diesel engine is highly efficient and needs servicing infrequently.
单选题In his speech at the conference, the Chairman solemnly stated that the responsibility to our lives and the kind of world {{U}}in that{{/U}} we live is ours and ours alone.
单选题The patient strongly objected to______like this.
单选题______ their final medical check, the astronauts boarded their spacecraft.
单选题At the end of the valley we turned right, and made for the summit. A. headed for B. went for C. looked for D. searched for
单选题Motivation is the driving force within individuals that impels them to action. A. impedes B. interferes C. holds D. pushes
单选题The most {{U}}striking{{/U}} technological success in the 20th century is probably the computer revolution.
单选题The hard, out surface of the tooth is called enamel. A. outside B. appearance C. outer D. hiding
单选题Teachers and nurses who deal with children are
obliged
to report cases of suspected child abuse to authorities.
单选题The shortage of rainfall this summer in the region is sure to cause ______ of vegetables for the food market. A. scarcity B. variety C. rarity D. validity
单选题Modem man is careless when disposing ______ his garbage. A. of B. to C. at D. about
单选题Pam loves children but she doesn't like them when they're noisy. It gets on her ______.
单选题When Mary discovered how treacherous the streets could be, she demanded that her boys stay close to her in the church gym and youth center, and the boys were {{U}}as good as gold{{/U}}, listening to every word she says.