sc question,thank you1!

redli

1)during R's years in office, black Americans began voting for Democrats rather than Republicans in national elections,but Black support for Democrats at the state and local levels (developed only after when civil rights legislation was supported by Harry Truman.)
B:developed only after when Harry Truman supported civil rights legislation
C:developed only after Harry Truman'support of civil rights legislation by Harry Truman
问题：答案C，当时我选了B，虽然感觉不是很好，但看C觉得很别扭。

2)Following the destruction of the space shuttle Challenger, investigators concluded that many key people employed by the National Aeronautics and Space Administration and its contractors work an excessive amount of (overtime that has the potential of causing) errors in judegment
Dvertime, a practice that has the potential for causing
Evertime, a practice that can, potentially, cause.
选E，我选了D，是否"potential"只有 the potential of doing 一种用法，我每选E是觉得它无端加了CAN，改变原意

lucylu

1.after与when连用是不对的，所以只能选C。去掉when可以考虑。
2.potential可用potential of doing sth or potential to do sth.但have potential for doing sth的用法极不规范。而且使用插入语也是ETS英语文法的要求之一。