路由器具有广播包抑制和子网隔离功能（）

影响工作表面粗糙度有下列因素：（）

A、磨床性能。

B、磨削用量。

C、砂轮粒度及其修整。

D、工件材料的力学性能。

E、切削液体的影响。

F、综合影响。

—Excuse, can you tell me ____?

—Sorry, I don’t. You can go to the information desk.

A．that there is a train

B．when the train goes

C．which train can I take

D．where does the train go.

景点讲解时怎样运用好简洁述说法？

患者红细胞与抗A及抗B产生凝集，其血清与A、B、O红细胞均不产生凝集，则此患者的血型为

A．A型
B．B型
C．O型
D．AB型
E．孟买型

Which of the following, if true, most logically completes the passage
Every fusion reaction releases neutrinos. To test a hypothesis about the frequency of fusion reactions in the Sun, physicists calculated the number of neutrinos the Sun would produce annually if the hypothesis were correct. From this they estimated how many neutrinos should pass through a particular location on Earth. The fact that far fewer neutrinos were counted than were predicted to pass through the location would seem to prove that the hypothesis is wrong, except that

A．the physicists, using a different method for estimating how many neutrinos should reach the location, confirmed their original estimate

B．there are several competing hypotheses about the frequency of solar fusion reactions

C．there is not enough energy in the Sun to destroy a neutrino once it is released

D．the method used to count neutrinos detects no more than approximately ten percent of the neutrinos that pass through

E．(E) neutrinos released in the fusion reactions of other stars also reach the Earth