[单选题]架空线路工程中，电杆中心与路由中心线的左右偏差不应大于50mm；除终端杆以外，电杆本身应( )。
A.上下平行
B.左右平行
C.上下垂直
D.左右垂直

Harvard University, breaking with a major trend in college admissions, will eliminate its early admissions program next year, with university officials arguing that such programs put low-income and minority applicants at a distinct disadvantage in the competition to get into selective universities.
For three decades Harvard has offered a particular form of early admissions, in which students who are accepted early still have the freedom to go elsewhere. Various forms of early admissions are offered by hundreds of colleges and universities, with many requiring applicants to commit upfront(预先) to attending the university if offered early admission.
The popularity of the procedure grew significantly in the 1990s, as colleges tried to increase their competitive advantage by locking in strong candidates early. But at Harvard and many other universities officials have grown concerned about that early admissions present a major obstacle to l