导致充电系统不能充电的原因可能有哪些？

两个质数相乘的积一定是奇数．______．

在团体保险产品的销售渠道组合策略中，远程策略强调直接回应广告、直接邮寄和中介三种方式，不包括面对面的接触。（ ）

A．对

B．错

三. 完形填空(20分，每小题2分)

Every year people in many countries___42___English. Some of them learn at school. __43___study by___44___ . But it is too hard__45___learn another language well. People must work very hard.

Why do all these people__46____to learn English? It’s difficult to__47____that question. Many boys and girls learn English at school or at college.___48___it is one of their ___49___.They study their own language ,math and physic…and English. Many adults learn English, because it is___50___in their work. They want to read newspaper, books and some others in English to get more knowledge. And that is why___51___people in the world will learn English.。

(    )42.  A. study       B. know       C. understand    D. speak

(    )43.  A. Others      B. other       C. The other    D. The others

(    )44.  A. they       B. their         C. them        D. themselves

(    )45.  A. that       B. as           C. for          D. to

(    )46  A. have        B. wish         C. need        D. want

(    )47.  A. think       B. answer       C. ask         D. talk

(    )48.  A. because     B. so           C. when        D. why

(    )49.  A. subject     B. the subject    C. subjects    D.a subject

(    )50.  A. interesting   B. difficult      C. easy        D. useful

(    )51.  A. more and more    B. many  more     C. fewer and fewer   D. most.

第二乳磨牙早失，第一恒磨牙尚未萌出或萌出不足者，应选择（）

A.远中导板保持器

B.功能性活动保持器

C.丝圈保持器

D.舌弓保持器

E.间隙扩展装置

经济纠纷的诉讼必须经过一审程序、二审程序才能发生法律效力。 ( )