專線

专 = 二 + ㇉ + ㇏ : Let's say the expert is a scientist. Also, 专 reminds me a little bit of the wheelchair symbol. Thus I choose a scientist in a wheelchair as symbol for 专.

专 = 二 + ㇉ + ㇏ : In front of the anthill, the scientist and Julian Giant Squid are focused on one thing: Electrifying the wheelchair of the scientist. Deeply concentrated they connect a capacitor to the wheelchair, which indeed starts to move a little.

线 = 戋 + 纟 : Mnemonic symbol: barbed wire.

线 = 戋 + 纟 : The silk worm wants to use the floating tank in the anthill's bathroom, but there's already Marie Curie inside—and she secured the tank by setting up barbed wire all around it.