Management of the project team is complicated ______ .

A．when team members are co-located

B．when minor problems do not impact the project completion date OE budget target

C．when team members are accountable to both a functional manager and the project manager

D．when formal training plans are implemented

化学纤维长度L（mm）和线密度Tt（Dtex）的比值一般为（）左右。

A、23

B、13

C、33

D、43