【C4】A．stillB．yetC．evenD．too

【C6】A．stillB．evenC．yetD．too

【C18】A．HoweverB．YetC．MoreoverD．Thus

【C5】A．neverB．yetC．alreadyD．since

【C4】A．ThenB．ThusC．EvenD．Indeed

【C17】A．stillB．yetC．alreadyD．often

【C8】A．neverthelessB．yetC．howeverD．though