[单项选择]Accordingly, a number of other methods have been employed.（　）
A. Therefore
B. Afterwards
C. However
D. Furthermore

[单项选择]A number of theories have been proposed to explain the situation.
A. suggested
B. tested
C. used
D. announced

[单项选择]A number of theories have been put forward about the possible causes of cancer.
A. 理论上早巳预言了癌症的病因。
B. 人们就造成癌症的病因提出了不少理论。
C. 大量的理论已经用于解释引发癌症的原因。
D. 人们已用大量理论来研究癌症的原因。

[单项选择]Recently a number of cases have been reported of young children ______ a violent act previously seen on television.
A. modifying
B. duplicating
C. accelerating
D. stimulating

[单项选择]Some other measures have been taken to reduce smoking such as ______.


A. changing the types of cigarette vending machines
B. clearing TV screens of cigarette advertising
C. passing laws to stop cigarette production
D. restricting the sale of cigarettes to special shops only

[单项选择]

Lately I have been noticing the great number of electrical appliances (电器) on the market. It seems to me that there are (1) now than a few years ago. I’ m not really (2) why this is so; (3) I do have a few (4) . The first is that we are just too (5) to do things by hand (6) For every little job we once had to do there is now a (7) . The seconds that electrical appliance companies are just trying to make (8) out of people’s laziness.
 (9) all of these electrical appliances around for us to use now, I (10) how I would have lived fifty years ago. (11) , how would I have cleaned my floor I guess I could have (12) one of those things called a "broom" , which I (13) see now.
I’m not trying to say I don’t (14) electrical appliances; I certainly (15) . It is hard for me to imagine (16) I would do without my hair dryer! (17) ，I do think a lot of modem appliances are needless and (18) may become even lazier by using them. (19) we&rsquo
A. ask
B. wonder
C. understand
D. remember