By mentioning 'thumb sucking', the author wants to prove that______.
A．some behaviors are common before the age of 5
B．children will stop some behaviors as they grow
C．many behaviors only happen when children drop out
D．some parents overreact to their children's behavior

未分类题The underlined phrase in Paragraph 3 refers to______.A．in great timeB．religiouslyC．very soonD．naturally

未分类题According to paragraph 2, what has stood in the way of print medias further development?A．The decline of advertising revenues.B．The spread of digital news.C．The over-high operating cost.D．The large office buildings.

未分类题夹紧装置由()组成。

未分类题It is indicated in the last paragraph thatA．leadership studies should focus more on judgment.B．businesspeople, leaders in particular, are versatile.C．strengths can turn into weakness sometimes.D．judgment is the most crucial measure of leadership.

未分类题机床夹具一般由()组成。