An overwhelming majority of Americans trust the news they get from network television, according to a poll conducted for U.S. News & World Report. The survey, by the Roper Organization, said 58% of respondents agreed that network news coverage is "neutral, objective and middle of the road." Twenty-two percent said TV news leans too far to the left and 10% said it is too far to the right. Networks got harsh marks, however, on questions of entertainment quality. Just 15% said they favored a takeover of CBS by Ted Turner, Atlanta businessman, who is making a hostile bid for the network.